Method and apparatus for reducing power consumption of terminal in wireless communication system

ABSTRACT

The disclosure relates to a communication scheme and system for convergence between an IoT technology and a 5G communication system for supporting a higher data transfer rate beyond a 4G system. The disclosure may be applied to intelligent services (e.g. smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, and security and safety-related services), based on a 5G communication technology and an IoT-related technology. In addition, the disclosure provides a method and an apparatus for reducing the power consumption of a terminal in a wireless communication system.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119to Korean Patent Application No. 10-2019-0174352, filed on Dec. 24,2019, in the Korean Intellectual Property Office, the disclosure ofwhich is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates generally to a method and an apparatus forreducing the power consumption of a terminal in a wireless communicationsystem.

2. Description of Related Art

To meet the increased demand for wireless data traffic since deploymentof fourth generation (4G) communication systems, efforts have been madeto develop an improved fifth generation (5G-) or pre-5G communicationsystem. Therefore, the 5G or pre-5G communication system is also calleda “beyond 4G network” or a “Post Long-Term Evolution System (LTE)”. The5G communication system is considered to be implemented in higherfrequency millimeter wave (mmWave) bands, e.g., 60 gigahertz (GHz)bands, so as to accomplish higher data rates. To decrease propagationloss of the radio waves and increase the transmission distance,beamforming techniques, massive multiple-input multiple-output (MIMO)techniques, full dimensional MIMO (FD-MIMO) techniques, array antennatechniques, analog beam forming techniques, and large scale antennatechniques are discussed in 5G communication systems. In addition, in 5Gcommunication systems, developments for system network improvement isunder way based on advanced small cells, cloud radio access networks(RANs), ultra-dense networks, device-to-device (D2D) communication,wireless backhaul technology, moving network technology, cooperativecommunication technology, coordinated multi-points (CoMP) technology,and reception-end interference cancellation technology. In the 5Gsystem, hybrid frequency shift keying (FSK) and quadrature amplitudemodulation (QAM) (FQAM) technology, sliding window superposition coding(SWSC) as an advanced coding modulation (ACM) technology, filter bankmulti carrier (FBMC) technology, non-orthogonal multiple access (NOMA)technology, and sparse code multiple access (SCMA) as an advanced accesstechnology have also been developed.

The Internet is now evolving to the Internet of things (IoT) wheredistributed entities, such as things, exchange and process informationwithout human intervention. The Internet of everything (IoE), which is acombination of the IoT technology and the big data processing technologythrough connection with a cloud server, has emerged. As technologyelements, such as “sensing technology”, “wired/wireless communicationand network infrastructure”, “service interface technology”, and“security technology” have been demanded for IoT implementation, asensor network, a machine-to-machine (M2M) communication network, and amachine type communication (MTC) network, have been recently researched.Such an IoT environment may provide intelligent Internet technologyservices that create a new value to human life by collecting andanalyzing data generated among connected things. IoT may be applied to avariety of fields including smart home fields, smart building fields,smart city fields, smart car or connected car fields, smart grid fields,health care fields, smart appliance fields and advanced medical servicefields through convergence and combination between existing informationtechnology (IT) and various industrial applications.

Various attempts have been made to apply 5G communication systems to IoTnetworks. For example, technologies such as a sensor networktechnologies, MTC technologies, and M2M communication technologies maybe implemented by beamforming, MIMO, and array antennas. Application ofa cloud radio access network (RAN), as the above-described big dataprocessing technology, may also be considered an example of convergenceof the 5G technology with the IoT technology.

In view of the above description, and considering the fact that variousservices can be provided as a result of the development of wirelesscommunication systems, a scheme for efficiently providing such servicesis needed. Particularly, there is a need for a communication method inwhich power consumed by terminals can be reduced in order to provideusers with services for a longer period of time.

SUMMARY

The present disclosure has been made to address the above-mentionedproblems and disadvantages, and to provide at least the advantagesdescribed below.

In accordance with an aspect of the disclosure, a method performed by aterminal is provided. The method includes receiving, from a basestation, information on a dormant bandwidth part (BWP) for a secondarycell; receiving, from the base station, downlink control information(DCI); and identifying information associated with a dormancy for thesecondary cell based on an information field included in the DCI, incase the DCI satisfies a predetermined condition, wherein an active BWPfor the secondary cell is identified based on the information associatedwith the dormancy for the secondary cell, and wherein monitoring of aphysical downlink control channel (PDCCH) is not performed by theterminal in case that the identified active BWP is the dormant BWP.

In accordance with another aspect of the disclosure, a terminal isprovided. The terminal includes a transceiver; and a controllerconfigured to receive, from a base station, information on a dormant BWPfor a secondary cell; receive, from the base station, DCI; and identifyinformation associated with a dormancy for the secondary cell based onan information field included in the DCI, in case the DCI satisfies apredetermined condition, wherein an active BWP for the secondary cell isidentified based on the information associated with the dormancy for thesecondary cell, and wherein monitoring of a PDCCH is not performed bythe terminal in case that the identified active BWP is the dormant BWP.

In accordance with another aspect of the disclosure, a method performedby a base station is provided. The method includes transmitting, to aterminal, information on a dormant BWP for a secondary cell; andtransmitting, to the terminal, DCI; wherein an information fieldincluded in the DCI is related to information associated with a dormancyfor the secondary cell, in case the DCI satisfies a predeterminedcondition, wherein an active BWP for the secondary cell is based on theinformation associated with the dormancy for the secondary cell, andwherein monitoring of a PDCCH is not performed by the terminal in casethat the identified active BWP is the dormant BWP.

In accordance with another aspect of the disclosure, a base station isprovided. The base station includes a transceiver; and a controllerconfigured to transmit, to a terminal, information on a dormant BWP fora secondary cell; and transmit, to the terminal, DCI; wherein aninformation field included in the DCI is related to informationassociated with a dormancy for the secondary cell, in case the DCIsatisfies a predetermined condition, wherein an active BWP for thesecondary cell is based on the information associated with the dormancyfor the secondary cell, and wherein monitoring of a PDCCH is notperformed by the terminal in case that the identified active BWP is thedormant BWP.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the present disclosure will be more apparent from thefollowing description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 illustrates a basic structure of a time-frequency domain of a 5Gsystem, according to an embodiment;

FIG. 2 illustrates frame, subframe, and slot structures of a 5G systemaccording to an embodiment;

FIG. 3 illustrates an example of a BWP configuration of a 5G system,according to an embodiment;

FIG. 4 illustrates an example of a control resource set (CORESET)configuration of a downlink control channel of a 5G system, according toan embodiment;

FIG. 5 illustrates a structure of a downlink control channel of a 5Gsystem, according to an embodiment;

FIG. 6 illustrates an example of a discontinuous reception (DRX)operation of a 5G system, according to an embodiment;

FIG. 7 illustrates a terminal operation, according to an embodiment;

FIG. 8 is a block diagram showing a structure of a terminal, accordingto an embodiment; and

FIG. 9 is a block diagram showing a structure of a base station,according to an embodiment.

DETAILED DESCRIPTION

An embodiment of the present disclosure seeks to provide a communicationmethod and an apparatus for reducing power consumed by a terminal in awireless communication system.

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings.

In describing embodiments of the disclosure, descriptions related totechnical contents well-known in the art and not associated directlywith the disclosure may be omitted. Such an omission of unnecessarydescriptions is intended to prevent obscuring of the main idea of thedisclosure and more clearly convey the main idea.

For the same reason, in the accompanying drawings, some elements may beexaggerated, omitted, or schematically illustrated. Further, the size ofeach element may not completely reflect the actual size. In thedrawings, identical or corresponding elements may be provided withidentical reference numerals.

The advantages and features of the disclosure and ways to achieve themwill be apparent by making reference to embodiments as described belowin detail in conjunction with the accompanying drawings. However, thedisclosure is not limited to the embodiments set forth below, but may beimplemented in various different forms. The following embodiments areprovided only to completely disclose the disclosure and inform thoseskilled in the art, and the disclosure is defined only by the scope ofthe appended claims. Throughout the specification, the same or likereference numerals may designate the same or like elements.

Hereinafter, a base station is configured to perform resource allocationto a terminal, and may be one of a gNode B, an eNode B, a Node B, a basestation, a wireless access unit, a base station controller, or a node ona network. A terminal may include a user equipment (UE), a mobilestation (MS), a cellular phone, a smartphone, a computer, or amultimedia system capable of a communication function. In thedisclosure, downlink (DL) denotes a wireless transmission path of asignal transmitted by a base station to a terminal, and uplink (UL)denotes a wireless transmission path of a signal transmitted by aterminal to a base station. In addition, hereinafter, although an LTE,LTE-Advanced (LTE-A), or 5G system may be described, an embodiment maybe also applied to communication systems having a similar technicalbackground or channel type. For example, the other communication systemsmay include a 5G mobile communication technology new radio (NR)technology developed after LTE-A, and 5G described below may also be aconcept including a conventional LTE and LTE-A and other servicessimilar thereto. In addition, the disclosure may be also applied toanother communication system through partial modification withoutdeparting too far from the scope of the disclosure according to thedetermination of a person skilled in the art.

Here, it will be understood that each block of the flowchartillustrations, and combinations of blocks in the flowchartillustrations, can be implemented by computer program instructions.These computer program instructions can be provided to a processor of ageneral purpose computer, a special purpose computer, or a programmabledata processing apparatus to produce a machine, such that instructions,which are executed via the processor of the computer or the programmabledata processing apparatus, create a means for implementing the functionsspecified in the flowchart block or blocks. These computer programinstructions may also be stored in a computer usable orcomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer usable orcomputer-readable memory produce an article of manufacture including aninstruction means that implements the function specified in theflowchart block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operational steps to be performed on the computeror other programmable apparatus to produce a computer implementedprocess such that the instructions that are executed on the computer orother programmable apparatus provide steps for implementing thefunctions specified in the flowchart block or blocks.

Further, each block of the flowchart illustrations may represent amodule, segment, or portion of code, which includes one or moreexecutable instructions for implementing the specified logicalfunction(s). It should also be noted that in some alternativeimplementations, the functions noted in the blocks may occur out of theorder. For example, two blocks shown in succession may in fact beexecuted substantially concurrently or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved.

As used herein, a “unit” refers to a software element or a hardwareelement, such as a field programmable gate array (FPGA) or anapplication specific integrated circuit (ASIC), which performs apredetermined function. However, the “unit” does not always have ameaning limited to software or hardware. The “unit” may be constructedeither to be stored in an addressable storage medium or to execute oneor more processors. Therefore, the “unit” includes, for example,software elements, object-oriented software elements, class elements ortask elements, processes, functions, properties, procedures,sub-routines, segments of a program code, drivers, firmware,micro-codes, circuits, data, databases, data structures, tables, arrays,and parameters. The elements and functions provided by the “unit” mayeither be combined into a smaller number of elements, or a “unit”, ordivided into a larger number of elements, or a “unit”. Moreover, theelements and “units” or may be implemented to reproduce one or morecentral processing units (CPUs) within a device or a security multimediacard. Further, the “unit” in the embodiments may include one or moreprocessors.

A wireless communication system has been developed to be a broadbandwireless communication system that provides a high speed and highquality packet data service, such as high speed packet access (HSPA),LTE, evolved universal terrestrial radio access (E-UTRA)), LTE-A, andLTE-Pro of 3^(rd) Generation Partnership Project (3GPP), high ratepacket data (HRPD), and ultra mobile broadband (UMB) of 3GPP 2 (3GPP2),and 802.16e of the Institute of Electrical and Electronics Engineers(IEEE). These services provide communication abilities beyond thevoice-based service provided at the initial stage.

An LTE system, which is a representative example of the broadbandwireless communication system, employs an orthogonal frequency divisionmultiplexing (OFDM) scheme for a downlink, and employs a single carrierfrequency division multiple access (SC-FDMA) scheme for an uplink.Uplink denotes a wireless link for transmitting data or a control signalby a terminal (a UE or an MS) to a base station (an eNode B), anddownlink denotes a wireless link for transmitting data or a controlsignal by a base station to a terminal. In the multiple access schemesdescribed above, time-frequency resources for carrying data or controlinformation may be allocated and managed in a manner to preventoverlapping of the resources between users, i.e. to establish theorthogonality, so as to identify data or control information of eachuser.

A future communication system after LTE, that is, a 5G communicationsystem, may be required to conveniently adhere to various requests froma user and/or a service provider, and thus support a service satisfyingall the various requirements. Services considered for 5G communicationsystems may include enhanced mobile broadband (eMBB), massive machinetype communication (mMTC), and ultra-reliability low-latencycommunication (URLLC).

The purpose of eMBB is to provide a data rate faster than a data ratesupported by the conventional LTE, LTE-A, or LTE-Pro. For example, in a5G communication system, eMBB may be required to provide a peak datarate of 10 gigabits per second (Gbps) for uplink and a peak data rate of20 Gbps for downlink in view of a single base station. Also, the 5Gcommunication system may be required to provide the peak data rates andan increased user perceived data rate of a terminal. In order to satisfythe requirements described above, a 5G communication system may requirethe improvement of various transmission/reception technologies includingfurther enhanced MIMO transmission technology. In addition, while LTEuses, for the transmission of a signal, a maximum transmission bandwidthof 20 megahertz (MHz) in a band of 2 GHz used by LTE, a 5G communicationsystem uses a frequency bandwidth greater than 20 MHz in a frequencyband of 3-6 GHz or a frequency band of 6 GHz or greater to satisfy adata transfer rate required for the 5G communication system.

Meanwhile, in a 5G communication system, mMTC has been considered tosupport application services such as the IoT. mMTC may require thesupport of a massive terminal connection in a cell, the improvement ofterminal coverage, an improved battery life, or a terminal costreduction in order to efficiently provide the IoT. Since the IoT ismounted in various sensors and devices to provide communicationfunctions, mMTC may be required to support a large number of terminals(e.g. 1,000,000 terminals/square kilometer (km2)) in a cell. Also, aterminal supporting mMTC may require a wider coverage compared to otherservices provided in a 5G communication system because it is highlyprobable that the terminal is disposed in a radio shadow area, such asthe basement of a building which a cell fails to cover due to the natureof the mMTC service. It may be necessary for a terminal supporting mMTCto be inexpensive and have a very long battery life, for example, 10 to15 years, because it is hard to frequently change the battery of theterminal.

Lastly, URLLC is a cellular-based wireless communication service whichmay be used for a mission-critical purpose. Services used to remotelycontrol robots or machinery, industrial automation devices, unmannedaerial vehicles, remote health care devices, or emergency alerts may beconsidered for URLLC. Therefore, communication provided by URLLC may berequired to provide very low latency and very high reliability. Aservice supporting URLLC may be required to satisfy a wirelessconnection latency time (i.e., an air interface latency) smaller than0.5 milliseconds and a packet error rate of 10⁻⁵ or smaller at the sametime. Therefore, for services supporting URLLC, a 5G system may requirea design for providing a transmission time interval (TTI) shorter thanthose of other services and allocating a wide domain of resources in afrequency band to secure the reliability of a communication link.

Three services of 5G, that is, eMBB, URLLC, and mMTC, may be multiplexedand then transmitted in a single system. In order to satisfy differentrequirements of the services, different transmission/reception schemesand different transmission/reception parameters may be used for theservices. However, 5G is not limited to the three aforementionedservices.

Hereinafter, a frame structure of a 5G system will be described indetail with reference to the drawings.

FIG. 1 illustrates a basic structure of a time-frequency domain that isa wireless resource region in which data or a control channel istransmitted, in a 5G system, according to an embodiment.

In FIG. 1, the transverse axis indicates a time domain, and thelongitudinal axis indicates a frequency domain. In the time-frequencydomain, a basic unit of a resource may be defined as a resource element(RE) 101, that is, one OFDM symbol 102 in a time axis and one subcarrier103 in a frequency axis. In the frequency domain, an N_(SC) ^(RB) number(e.g. 12) of consecutive REs may configure a single resource block (RB)104.

FIG. 2 illustrates a slot structure considered in a 5G system, accordingto an embodiment.

FIG. 2 illustrates an example of a structure of a frame 200, a subframe201, a first slot 202 and a second slot 203. One frame 200 may bedefined as 10 milliseconds. One subframe 201 may be defined as 1millisecond, and thus one frame 200 may be configured by a total of 10subframes 201. The first slot 202 and/or the second slot 203 may bedefined as 14 OFDM symbols (i.e. the number (N_(symb) ^(slot)) ofsymbols per one slot=14). One subframe 201 may be configured by thefirst slot 202 and/or the second slot 203, and the number of slots perone subframe 201 may be different according to a configuration value μ204 and/or a configuration value μ 205 of subcarrier spacing. FIG. 2illustrates an example in which a subcarrier spacing configuration valueμ is 0 (the case indicated by reference numeral 204), and a subcarrierspacing configuration value μ is 1 (the case indicated by referencenumeral 205). If μ 204 is 0, one subframe 201 may be configured by oneslot 202, and if μ 205 is 1, one subframe 201 may be configured by twoslots 203. That is, the number (N_(slot) ^(subframe,μ)) of slots per onesubframe may be different according to a configuration value μ of asubcarrier spacing, and according thereto, the number (N_(slot)^(frame,μ)) of slots per one frame may be different. N_(slot)^(subframe,μ)   and N_(slot) ^(frame,μ)   according to each subcarrierspacing configuration μ may be defined as shown below in Table 1.

TABLE 1 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16 5 14 320 32

Next, a BWP configuration in a 5G communication system will be describedin detail with reference to the drawings.

FIG. 3 illustrates an example of a configuration of a BWP in a 5Gcommunication system, according to an embodiment.

FIG. 3 illustrates an example in which a terminal bandwidth (a UEbandwidth) 300 is configured to be divided into two BWPs, that is, BWP#1 301 and BWP #2 302. A base station may configure one BWP or multipleBWPs for a terminal and may configure pieces of information for each BWPas shown below in Table 2.

TABLE 2 BWP ::= SEQUENCE {  bwp-Id BWP-Id,  (BWP identifier) locationAndBandwidth INTEGER (1..65536),  (BWP location) subcarrierSpacing ENUMERATED {n0, n1, n2, n3, n4, n5},  (Subcarrierspacing)  cyclicPrefix ENUMERATED { extended }  (Cyclic prefix) }

However, the disclosure is not limited to the example shown in Table 2.In addition to the pieces of configuration information described above,various parameters related to a BWP may be configured for the terminal.The pieces of information may be transferred by the base station to theterminal through higher layer signaling, for example, radio resourcecontrol (RRC) signaling. At least one BWP among the configured one BWPor multiple BWPs may be activated. Whether the configured BWP isactivated may be semi-statically transferred from the base station tothe terminal through RRC signaling, or dynamically transferred throughDCI.

An initial BWP for an initial access may be configured for the terminalbefore an RRC connection by the base station through a masterinformation block (MIB). More specifically, a terminal may receiveconfiguration information relating to a CORESET and a search space, inwhich a PDCCH may be transmitted, the PDCCH being designed for theterminal to receive system information (the system information maycorrespond to remaining system information (RMSI) or system informationblock 1 (SIB1)) required for an initial access through an MIB in aninitial access stage. A CORESET and a search space that are configuredthrough an MIB may be assumed to be identifiers (identities (IDs)). Thebase station may notify the terminal of configuration information suchas frequency allocation information, time allocation information, andnumerology for a CORESET #0 through an MIB. In addition, the basestation may notify, through an MIB, the terminal of configurationinformation relating to a monitoring period and occasion for CORESET #0,that is, configuration information relating to search space #0. Theterminal may consider a frequency region configured to be CORESET #0obtained from an MIB, as an initial BWP for an initial access. The ID ofthe initial BWP may be considered to be 0.

The BWP configuration supported by 5G may be used for various purposes.

If a bandwidth supported by the terminal is smaller than a systembandwidth, the terminal may be supported through the BWP configuration.For example, the base station may configure the frequency location(configuration information 2) of a BWP for the terminal so that theterminal transmits or receives data at a particular frequency locationin a system bandwidth.

In addition, the base station may configure a plurality of BWPs for aterminal in order to support different numerologies. For example, inorder to support, to/from a terminal, both data transmission/receptionusing a subcarrier spacing of 15 KHz and data transmission/receptionusing a subcarrier spacing of 30 KHz, the base station may configure,for the terminal, two BWPs having a subcarrier spacing of 15 KHz and asubcarrier spacing of 30 KHz, respectively. Different BWPs may undergofrequency division multiplexing (FDM), and if the terminal and the basestation are to transmit or receive data using a particular subcarrierspacing, a BWP configured to have the subcarrier spacing may beactivated.

In addition, the base station may configure BWPs having differentbandwidths for the terminal in order to reduce the power consumption ofthe terminal. For example, if the terminal supports a very widebandwidth, for example, a bandwidth of 100 MHz, and always transmits orreceives data through the bandwidth, the terminal may consume a verylarge quantity of power. Particularly, unnecessary monitoring of adownlink control channel in a large bandwidth of 100 MHz under notraffic may be very inefficient in view of power consumption. In orderto reduce the power consumption of a terminal, the base station mayconfigure a BWP having a relatively small bandwidth, for example, a BWPhaving 20 MHz, for the terminal. If there is no traffic, the terminalmay monitor a 20 MHz BWP, and if data is generated, the terminal maytransmit or receive the data through a 100 MHz BWP according to anindication of the base station.

In relation to a method configuring a BWP described above, terminals,before communication via an RRC connection, may receive configurationinformation of an initial BWP through an MIB in an initial access stage.More specifically, a CORESET for a downlink control channel throughwhich DCI scheduling an SIB can be transmitted may be configured for theterminal through an MIB of a physical broadcast channel (PBCH). Thebandwidth of the CORESET configured by the MIB may be considered as aninitial BWP, and the terminal may receive a physical downlink sharedchannel (PDSCH) through which the SIB is transmitted, through theconfigured initial BWP. An initial BWP may be used for other systeminformation (OSI), paging, and random access in addition to thereception of a SIB.

If one or more BWPs are configured for the terminal, the base stationmay instruct the terminal to change a BWP, by using a BWP indicatorfield in the DCI. For example, in FIG. 3, if a currently activated BWPof the terminal is BWP #1 301, the base station may indicate BWP #2 302for the terminal through a BWP indicator in DCI, and the terminal maychange the BWP to BWP #2 302 indicated by the BWP indicator in thereceived DCI.

As described above, a BWP change based on DCI may be indicated by DCIscheduling a PDSCH or a PUSCH, and thus if a terminal receives a BWPchange request, the terminal is required to smoothly transmit or receivethe PDSCH or PUSCH scheduled by the DCI in a changed BWP. To this end, astandard prescribes a requirement for a latency time interval (T_(BWP))required for a BWP change, and the requirements may be defined, forexample, as shown below in Table 3.

TABLE 3 NR Slot length (milli- BWP switch delay T_(BWP) (slots) μseconds) Type 1^(Note 1) Type 2^(Note 1) 0 1 [1]  [3] 1 0.5 [2]  [5] 20.25 [3]  [9] 3 0.125 [6] [17] Note 1: Depends on UE capability. Note 2:If the BWP switch involves changing of SCS, the BWP switch delay isdetermined by the larger one between the SCS before BWP switch and theSCS after BWP switch.

The requirements for a BWP change latency time interval may support type1 or type 2 according to the capability of the terminal. The terminalmay report a supportable type of BWP latency time interval to the basestation.

According to the above requirement for BWP change latency time interval,if the terminal receives DCI including a BWP change indicator in slot n,the terminal may complete changing to a new BWP indicated by the BWPchange indicator at a time point not later than slot n+T_(BWP), andtransmit or receive a data channel scheduled by the DCI in the changednew BWP. If the base station is to schedule a data channel in a new BWP,the base station may determine time domain resource allocation for thedata channel in consideration of a BWP change latency time interval(T_(BWP)) of the terminal. That is, in a method of determining timedomain resource allocation for a data channel when the base stationschedules the data channel in a new BWP, the data channel may bescheduled after a BWP change latency time interval. Accordingly, theterminal may not expect that DCI indicating a change of a BWP indicatesa slot offset (K0 or K2) value smaller than a BWP change latency timeinterval (T_(BWP)).

If the terminal receives DCI (e.g. DCI format 1_1 or 0_1) indicating achange of a BWP, the terminal may not perform any transmission orreception during a time interval from the third symbol of a slotreceiving a PDCCH including the DCI to the starting point of a slotindicated by a slot offset (K0 or K2) value indicated by a time domainresource allocation indicator field in the DCI. For example, if theterminal receives a DCI indicating a change of a BWP in slot n, and aslot offset value indicated by the DCI is K, the terminal may notperform any transmission or reception during a time interval from thethird symbol of slot n to the symbol before slot n+K (i.e. the lastsymbol of slot n+K−1).

Next, a synchronization signal (SS)-PBCH block in 5G is described.

An SS/PBCH block may denote a physical layer channel block including aprimary SS (PSS), a secondary SS (SSS), and a PBCH. A PSS may be asignal serving as a criterion of downlink time/frequencysynchronization, and provide partial information of a cell ID. An SSSmay be a signal serving as a criterion of downlink time/frequencysynchronization, and provide the remaining cell ID information which isnot provided by a PSS. Additionally, an SSS may serve as a referencesignal for demodulation of a PBCH. A PBCH may provide essential systeminformation required for transmission/reception for a data channel and acontrol channel of a terminal. The essential system information mayinclude search space-related control information indicating wirelessresource mapping information of a control channel, and schedulingcontrol information relating to a separate data channel through whichsystem information is transmitted. An SS/PBCH block may be configured bya combination of a PSS, an SSS, and a PBCH. One or multiple SS/PBCHblocks may be transmitted within a time of 5 milliseconds, and eachtransmitted SS/PBCH block may be identified by an index.

The terminal may detect a PSS and an SSS in an initial access stage, andmay decode a PBCH. The terminal may obtain MIB from the PBCH, andCORESET #0 (this may correspond to a CORESET having a CORESET index of0) may be configured for the terminal from the MIB. The terminal maymonitor CORESET #0 under the assumption that an SS/PBCH block selectedby the terminal and a demodulation reference signal (DMRS) transmittedin CORESET #0 are quasi-co-located (QCL). The terminal may receivesystem information through DCI transmitted in CORESET #0. The terminalmay obtain random access channel (RACH)-related configurationinformation for initial access from the received system information. Theterminal may transmit a physical RACH (PRACH) to the base station inconsideration of the selected SS/PBCH index, and the base station thatreceived the PRACH may obtain information relating to the index of theSS/PBCH block selected by the terminal. The base station may identifythat the terminal selects a block among SS/PBCH blocks, and monitorCORESET #0 associated with the block.

In the following description, DCI in a 5G system will be explained indetail.

In a 5G system, scheduling information on uplink data (or a physicaluplink data channel or a PUSCH) or downlink data (or a physical downlinkdata channel or a PDSCH) is transferred through DCI from a base stationto a terminal. The terminal may monitor a fallback DCI format and anon-fallback DCI format for a PUSCH or a PDSCH. The fallback DCI formatmay be configured by a fixed field pre-defined between a base stationand a terminal, and the non-fallback DCI format may include aconfigurable field.

DCI may undergo a channel coding and modulation process, and then betransmitted through a PDCCH. A cyclic redundancy check (CRC) may beattached to a DCI message payload, and the CRC may be scrambled by aradio network temporary identifier (RNTI) corresponding to the identityof the terminal. Different types of RNTIs may be used according to thepurpose of a DCI message, for example, terminal (UE)-specific datatransmission may be used, a power control command may be used, or arandom access response may be used. That is, an RNTI may not beexplicitly transmitted, and may be transmitted after being included in aCRC calculation process. If the terminal has received a DCI messagetransmitted on a PDCCH, the terminal may identify a CRC by using anassigned RNTI, and if a CRC identification result is correct, theterminal may identify that the message has been transmitted to theterminal.

For example, DCI scheduling a PDSCH for system information (SI) may bescrambled by a SI-RNTI. DCI scheduling a PDSCH for a random accessresponse (RAR) message may be scrambled by a RA-RNTI. DCI scheduling aPDSCH for a paging message may be scrambled by a P-RNTI. DCI notifyingof a slot format indicator (SFI) may be scrambled by a SFI-RNTI. DCInotifying of a transmit power control (TPC) may be scrambled by aTPC-RNTI. DCI scheduling a terminal-specific PDSCH or PUSCH may bescrambled by a cell RNTI (C-RNTI).

DCI format 0_0 may be used for fallback DCI scheduling a PUSCH, and inthis case, a CRC may be scrambled by a C-RNTI. DCI format 0_0 having aCRC scrambled by a C-RNTI may include, for example, the informationshown in Table 4, below.

TABLE 4 Identifier for DCT formats-1 bit  The value of this bit field isalways set to 0,  indicating an UL DCI format Frequency domain resourceassignment - ┌log₂(N_(RB) ^(UL,BWP)( N_(RB) ^(UL,BWP) + 1)/2 )┐ bitswhere N_(RB) ^(UL,BWP) is defined in subclause 7.3.1.0  For PUSCHhopping with resource allocation type 1:   N_(UL)_hop MSB bits are usedto indicate the frequency offset according   to Subclause 6.3 of [6, TS38.214], where N_(UL)_hop = 1 if the higher   layer parameterfrequencyHoppingOffsetLists contains two offset   values and N_(UL)_hop= 2 if the higher layer parameter   frequencyHoppingOffsetLists containsfour offset values   ┌log₂(N_(RB) ^(UL,BWP)( N_(RB) ^(UL,BWP) + 1)/2 )┐ - N_(UL)_hop bits provides the   frequency domain resource allocationaccording to Subclause   6.1.2.2.2 of [6, TS 38.214]  For non-PUSCHhopping with resource allocation type 1:    ┌log₂(N_(RB) ^(UL,BWP)(N_(RB) ^(UL,BWP) + 1)/2 ) ┐ bits provides    the frequency domainresource allocation according    to Subclause 6.1.2.2.2 of [6, TS38.214]  Time domain resource assignment-4 bits as defined in  Subclause6.1.2.1 of [6, TS 38.214]  Frequency hopping flag-1 bit according toTable 7.3.1.1.1-3,  as defined in Subclause 6.3 of [6, TS 38.214] Modulation and coding scheme-5 bits as defined in  Subclause 6.1.4.1 of[6, TS 38.214]  New data indicator-1 bit  Redundancy version-2 bits asdefined in Table 7.3.1.1.1-2  HARQ process number-4 bits  TPC commandfor scheduled PUSCH-2 bits as defined in  Subclause 7.1.1 of [5, TS38.213]  Padding bits, if required.  UL/SUL indicator-1 bit for UEsconfigured  with supplementatyUplink in  ServingCellConfig in the cellas defined in  Table 7.3.1.1.1-1 and the  number of bits for DCI format1_0 before padding  is larger than the number  of bits for DCI format0_0 before padding;  0 bit otherwise. The UL/SUL  indicator, if present,locates in the last bit position  of DCI format 0_0, after the paddingbit (s).  If the UL/SUL indicator is present in DCI format  0_0 and thehigher  layer parameter pusch-Config is not configured on  both UL andSUL the  UE ignores the UL/SUL indicator field in DCI  format 0_0, andthe  corresponding PUSCH scheduled by the DCI  format 0_0 is for the UL or SUL for which high layer parameter pucch-  Config is configured;  If the UL/SUL indicator is not present in DCI   format 0_0 and pucch-  Config is configured, the corresponding PUSCH   scheduled by the DCI  format 0_0 is for the UL or SUL for which high   layer parameterpucch-Config is configured.  If the UL/SUL indicator is not present inDO  format 0_0 and pucch-Config  is not configured, the correspondingPUSCH  scheduled by the DCI format  0_0 is for the uplink on which thelatest PRACH is transmitted.

DCI format 0_1 may be used for non-fallback DCI scheduling a PUSCH, andin this case, a CRC may be scrambled by a C-RNTI. DCI format 0_1 havinga CRC scrambled by a C-RNTI may include, for example, the informationshown in Table 5, below.

TABLE 5 Identifier for DCI formats-1 bit  The value of this bit field isalways set to 0,  indicating an UL DCI format Carrier indicator-0 or 3hits, as defined in Subclause 10.1 of [5, TS38.213]. UL/SUL indicator-0bit for UEs not configured with supplementaryUplink in ServingCellConfigin the cell or UEs configured with supplementaryUplink inServingCellConfig in the cell but only PUCCH carrier in the cell isconfigured for PUSCH transmission; otherwise, 1 bit as defined in Table7.3.1.1.1-1. Bandwidth part indicator-0, 1 or 2 bits as determined bythe number of UL BWPs n_(BWP,RRC) configured by higher layers, excludingthe initial UL bandwidth part. The bitwidth for this field is determinedas ┌log₂(n_(BWP))┐ bits, where  n_(BWP) = n_(BWP,RRC) +1 if n_(BWP,RRC)≤3, in which  case the bandwidth part indicator is equivalent  to theascending order of the higher layer  pararneter BWP-Id;  otherwisen_(BWP) = n_(BWP,RRC), in which case  the bandwidth part indicator  isdefined in Table 7.3.1.1.2-1; If a UE does not support active BWP changevia DCI,  the UE ignores this bit field. Frequency domain resourceassignment-number of bits determined by the following, where N_(RB)^(UL,BWP) is the size of the active UL bandwidth part:  N_(RBG) bits ifonly resource allocation type 0  is configured, where N_(RBG) is definedin   Subclause 6.1.2.2.1 of [6, TS 38.214],  ┌log₂(N_(RB) ^(UL,BWP)(N_(RB) ^(UL,BWP) + 1)/2 )┐ bits if  only resource allocation type  1 isconfigured, or max (┌log₂(N_(RB) ^(UL,BWP)( N_(RB) ^(UL,BWP) + 1)/2 )┐, N_(RBG)) + 1 bits if both resource allocation type 0 and 1 are configured.  If both resource allocation type 0 and 1 are configured, the MSB bit is used to indicate resource allocation   type 0 orresource allocation type 1, where the bit  value of 0 indicates resourceallocation type 0 and the bit  value of 1 indicates resource allocationtype 1.  For resource allocation type 0, the N_(RBG) LSBs  provide theresource allocation as defined in  Subclause 6.1.2.2.1 of [6, TS38.214].  For resource allocation type 1, the  ┌log₂(N_(RB) ^(UL,BWP)(N_(RB) ^(UL,BWP) + 1)/2 )┐  LSBs provide the resource allocation asfollows:   For PUSCH hopping with resource allocation type 1:   N_(UL)_hop MSB bits are used to indicate the frequency offset   according to Subclause 6.3 of [6, TS 38.214], N_(UL)_hop = 1    ifthe higher layer parameter fequencyfloppingOffsetLists    contains twooffset values and N_(UL)_hop = 2 if the higher layer    parameterfrequencyHoppingOffsetLists contains four offset    values    ┌log₂(N_(RB) ^(UL,BWP)( N_(RB) ^(UL,BWP) + 1)/2 )┐ - N_(UL)_hop bits    provides the frequency domain resource allocation     according toSubclause 6.1.2.2.2 of [6, TS 38.214]    For non-PUSCH hopping withresource allocation type 1:     ┌log₂(N_(RB) ^(UL,BWP)( N_(RB)^(UL,BWP) + 1)/2 )┐ bits provides the     frequency domain resourceallocation according to     Subclause 6.1.2.2.2 of [6, TS 38.214]   If“Bandwidth part indicator” field indicates   a bandwidth part other than  the active bandwidth part and if both resource   allocation type 0 and1   are configured for the indicated bandwidth   part, the UE assumes  resource allocation type 0 for the indicated   bandwidth part if the  bitwidth of the “Frequency domain resource   assignment” field of the  active bandwidth part is smaller than the   bitwidth of the “Frequency  domain resource assignment” field of the   indicated bandwidth part.Time domain resource assignment-0, 1, 2, 3, or 4 bits as defined inSubclause 6.1.2.1 of [6, TS38.214]. The bitwidth for this feild isdetermined as ┌log₂(1)┐ bits, where is the number of entries in thehigher layer parameter pusch-TimeDomainAllocationList if the higherlayer parameter is configured; otherwise 1 is the number of entries inthe default table. Frequency hopping flag-0 or 1 bit:  0 bit if onlyresource allocation type 0 is configured or if the  higher layerparameterfrequencyHopping is not configured;  1 bit according to Table7.3.1,1.1-3 otherwise,  only applicable to resource allocation type 1, as defined in Subclause 6.3 of [6, TS 38.214]. Modulation and codingscheme-5 bits as defined in Subclause 6.1.4,1 of [6, TS 38.214] New dataindicator-1 bit Redundancy version-2 bits as defined in Table7.3.1.1.1-2 HARQ process number-4 bits 1^(st) downlink assignmentindex-1 or 2 bits:  1 bit for semi-static HARQ-ACK codebook  2 bits fordynamic HARQ-ACK codebook, 2^(nd) downlink assignment index-0 or 2 bits: 2 bits for dynamic HARQ-ACK codebook with two HARQ-  ACK sub-codebooks 0 bit otherwise. TPC command for scheduled PUSCH-2 bits as defined inSubdause 7.1.1 of [5, TS38.213]  

 

SRS resource indicator - ┌log₂((Σ_(k=1) ^(min{LSRS) ^(max{}}Σ) (N_(k)^(SRS))())┐ or ┌log₂(N_(SRS))┐ bits, where N_(SRS) is the number ofconfigured SRS resources in the SRS resource set associated with thehigher layer parameter usage of value ‘codeBook’ or ‘nonCodeBook’, 

 

 ┌log₂(Σ_(k=1) ^(min{LSRS) ^(max{}}Σ) (N_(k) ^(SRS))())┐bits accordingto Tables  7.3.1.1.2-28/29/30/31 if the higher layer parameter txConfig=  nonCodebook, where N_(SRS) is the number of configured  SRS resourcesin the SRS resource set associated with the  higher layer parameterusage of value ‘nonCodeBook’ and   if UE supports operation withmaxMIMO-Layers and the   higher layer parameter maxMIMO-Layerss ofPUSCH-   ServingCellConfig of the serving cell is configured,   L_(max)is given by that parameter otherwise, L_(max) is   given by the maximumnumber of layers forPUSCH   supported by the UE for the serving cell fornon-codebook   based operation.  ┌log₂(N_(SRS))┐ bits according toTables 7.3.1.1.2-32 if the  higher layer parameter txConfig = codebook,where N_(SRS)  is the number of configured SRS resources in the SRS resource set associated with the higher layer parameter  usage of value‘codeBook’. Precoding information and number of layers-number of bitsdetermined by the following:  0 bits if the higher layer parametertxConfig = nonCodeBook;  0 bits for 1 antenna port and if the higherlayer parameter  txConfig = codebook;  4, 5, or 6 bits according toTable 7.3.1.1.2-2 for 4 antenna  ports, if txConfig = codebook, andaccording to whether  transform precoder is enabled or disabled, and the values of higher layer parameters maxRank  and codebookSubset;  2, 4,or 5 bits according to Table 7.3.1.1.2-3 for 4 antenna  ports, iftxConfig = codebook, and according to whether  transform precoder isenabled or disabled, and the  values of higher layer parameters maxRank, and code bookSubset;  2 or 4 bits according to Table7.3.1 .1.2-4 for 2antenna  ports, if txConfig = codebook, and according to whether transform precoder is enabled or disabled, and the  values of higherlayer parameters maxRank and  codebookSubset;  1 or 3 bits according toTable7.3.1.1.2-5 for 2 antenna  ports, if txConfig = codebook, andaccording to whether  transform precoder is enabled or disabled, and the values of higher layer parameters maxRank and  codebookSubset. Antennaports - number of bits determined by the following  2 bits as defined byTables 7.3.1.1.2-6, if transform  precoder is enabled, dmrs-Type=1, andmaxLength=1;  4 bits as defined by Tables 7.3.1.1.2-7, if transform precoder is enabled, dmrs-Type=1, and maxLength=2;  3 bits as definedby Tables 7.3.1.1.2-8/9/10/11,  if transform precoder is disabled,dmrs-Type=1, and  maxLength=1, and the value of rank is determinedaccording  to the SRS resource indicator field if the higher layer parameter txConfig = nonCodebook and according to the  Precodinginformation and number of layers field if the  higher layer parametertx.Config = codebook;  4 bits as defined by Tables 7.311.2-12/13/14/15, if transform precoder is disabled, dmrs-Type=1, and  maxLength=2, andthe value of rank is determined according  to the SRS resource indicatorfield if the higher layer  parameter txConfig = nonCodebook andaccording to the  Precoding information and number of layers field ifthe  higher layer parameter txConfig = codebook;  4 bits as defined byTables 7.3,112-16/17/18/19,  if transform precoder is disabled,dmrs-Type=2, and  maxLength=1, and the value of rank is determinedaccording  to the SRS resource indicator field if the higher layer parameter txConfig = nonCode book and according to the  Precodinginformation and number of layers field if the  higher layer parametertxConfig = codebook.  5 bits as defined by Tables 7.3,1.1.2-20/21/22/23, if transform precoder is disabled, dmrs-Type=2, and  maxLengin=2, andthe value of rank is determined according  to the SRS resource indicatorfield if the higher layer  parameter tx-Contig = nonCodebook andaccording to the  Precoding information and number of layers field ifthe  higher layer parameter txConfig = codebook. where the number of CDMgroups without data of values 1, 2, and 3 in Tables 7.3.1.1.2-6 to7.3.1.1.2-23 refers to CDM groups {0}, {0,1}, and {0, 1,2} respectively.If a UE is configured with both dmrs-UplinkForPUSCH- MappingTypeA anddmrs-UplinkForPUSCH-MappingTypeB, the bitwidth of this field equalsmax{x_(A), x_(B)}, where x_(A) is the “Antenna ports” bitwidth derivedaccording to dmrs- UplinkForPUSCH-MappingTypeA and x_(B) is the “Antennaports” bitwidth derived according to dmrs-UplinkForPUSCH- MappingTypeB.A number of |x_(A) - x_(B)| zeros are padded in the MSB of this field,if the mapping type of the PUSCH corresponds to the smaller value ofx_(A) and x_(B). SRS request - 2 bits as defined by Table 7.3.1 .1.2-24for UEs not configured with supplementaryUplink in ServingCellConfig inthe cell; 3 bits for UEs configured with supplementatyUplink inServingCellConfig in the cell where the first bit is the non-SUL/SULindicator as defined in Table 7.3.1.1.1-1 and the second and third bitsare defined by Table 7.3.1.1.2-24. This bit field may also indicate theassociated CSI-RS according to Subclause 6.1.1.2 of [6, TS 38.214]. CSIrequest - 0, 1, 2, 3, 4, 5, or 6 bits determined by higher layerparameter reportTriggerSize. CBG transmission information (CBGTI) - 0bit if higher layer parameter codeBlockGroupTransmission for PDSCH isnot configured, otherwise, 2, 4, 6, or 8 bits determined by higher layerparameter maxCodeBlockGroupsPerTransportBlock for PUSCH. PTRS-DMRSassociation - number of bits determined as follows  0 bit ifPTRS-UplinkConfig is not configured  and transform precoder is disabled, or if transform precoder is enabled,  or if maxRank=1;  2bits otherwise, where Table 7.3.1.1.2-25  and 7.3.1.1.2-26 are used to indicate the association between PTRS  port(s) and DMRS port(s) for transmission of one PT-RS port and  two PT-RS ports respectively, and the DMRS ports are indicated by the Antenna ports field. If “Bandwidthpart indicator” field indicates a bandwidth part other than the activebandwidth part and the “PTRS-DMRS association” field is present for theindicated bandwidth part but not present for the active bandwidth part,the UE assumes the “PTRS-DMRS association” field is not present for theindicated bandwidth part. beta_offset indicator - 0 if the higher laverparameter betaOffsets = semiStatic otherwise 2 bits as defined by Table9.3-3 in [5, TS 38.213]. DMRS sequence initialization - 0 bit iftransform precoder is enabled; 1 bit if transform precoder is disabled.UL-SCH indicator - 1 bit. A value of “1” indicates UL-SCH shall betransmitted on the PUSCH and a value of “0” indicates UL-SCH shall notbe transmitted on the PUSCH. Except for DCI format 0_1 with CRCscrambled by SP-CSI-RNTI, a UE is not expected to receive a DCI format0_1 with UL-SCH indicator of “0” and CSI request of all zero(s).

DCI format 1_0 may be used for fallback DCI scheduling a PDSCH, and inthis case, a CRC may be scrambled by a C-RNTI. DCI format 1_0 having aCRC scrambled by a C-RNTI may include, for example, the informationshown in Table 6, below.

TABLE 6  Identifier for DCI formats - 1 bits   The value of this bitfield is always set to 1, indicating a DL DCI   format  Frequency domainresource assignment - ┌log2(N_(RB) ^(DL,BWP)(N_(RB) ^(DL,BWP)  1)/2)┐bits where N_(RB) ^(DL,BWP) is given by subclause 7.3.1.0 If the CRC ofthe DCI format 1_0 is scrambled by C-RNTI and the “Frequency domainresource assignment” field are of all ones, the DCI format 1_0 is forrandom access procedure initiated by a PDCCH order, with all remainingfields set as follows:  Random Access Preamble index - 6 bits accordingto ra-Preambleindex  in Subclause 5.1.2 of [8, TS38.321]  UL/SULindicator - 1 bit. If the value of the “Random Access Preamble  index”is not all zeros and if the UE is configured with  supplementaryUplinkin ServingCellConfig in the cell, this field  indicates which UL carrierin the cell to transmit the PRACH according  to Table 7.3.1.1.1-1;otherwise, this field is reserved  SS/PBCH index - 6 bits. If the valueof the “Random Access Preamble  index” is not all zeros, this fieldindicates the SS/PBCH that shall be  used to determine the RACH occasionfor the PRACH transmission;  otherwise, this field is reserved.  PRACHMask index - 4 bits. If the value of the “Random Access  Preamble index”is not all zeros, this field indicates the RACH occasion   associatedwith the SS/PBCH indicated by “SS/PBCH index” for the  PRACHtransmission, according to Subclause 5.1.1 of [8, TS38.321];  otherwise,this field is reserved  Reserved bits - 10 bits Otherwise, all remainingfields are set as follows:  Time domain resource assignment - 4 bits asdefined in Subclause  5.1.2.1 of [6, TS 38.214]  VRB-to-PRB mapping - 1bit according to Table 7.3.1.2.2-5  Modulation and coding scheme - 5bits as defined in Subclause 5.1.3  of [6, TS 38.214]  New dataindicator - 1 bit  Redundancy version - 2 bits as defined in Table7.3.1.1.1-2  HARQ process number - 4 bits  Downlink assignment index - 2bits as defined in Subclause 9.1.3 of  [5, TS 38.213], as counter DAI TPC command for scheduled PUCCH - 2 bits as defined in Subclause  7.2.1of [5, TS 38.213]  PUCCH resource indicator - 3 bits as defined inSubclause 9.2.3 of  [5, TS 38.213]  PDSC/H-to-HARQ_feedback timingindicator - 3 bits as defined in  Subclause 9.2.3 of [5, TS38.213]

DCI format 1_1 may be used for non-fallback DCI scheduling a PDSCH, andin this case, a CRC may be scrambled by a C-RNTI. DCI format 1_1 havinga CRC scrambled by a C-RNTI may include, for example, the informationshown in Table 7, below.

TABLE 7  Identifier for DCI formats - 1 bits   The value of this bitfield is always set to 1, indicating a DL DCI   format  Carrierindicator - 0 or 3 bits as defined in Subclause 10.1 of [5, TS  38.213] Bandwidth part indicator - 0, 1 or 2 bits as determined by the numberof  DL BWPs n_(BWP,RRC) configured by higher layers, excluding theinitial  DL bandwidth part. The bitwidth for this field is determined as ┌log₂(n_(BWP))┐ bits, where   n_(BWP) = n_(BWP,RRC) + 1 if n_(BWP,RRC)≤ 3, in which case the bandwidth   part indicator is equivalent to theascending order of the higher layer   parameter BWP-Id;   otherwisen_(BWP) = n_(BWP,RRC), in which case the bandwidth part   indicator isdefined in Table 7.3.1.1.2-1;  If a UE does not support active BWPchange via DCI, the UE ignores   this bit field.  Frequency domainresource assignment - number of bits determined by  the following, whereN_(RB) ^(DL,BWP) is the size of the active DL bandwidth  part:  N_(RBG)bits if only resource allocation type 0 is configured, where N_(RBG)  isdefined in Subclause 5.1.2.2.1 of [6, TS38.214],  ┌log₂ (N_(RB)^(DL,BWP) (N_(RB) ^(DL,BWP) + 1)/2)┐ bits if only resource allocation type 1 is configured, or  max (┌log₂(N_(RB) ^(DL,BWP) (N_(RB)^(DL,BWP) + 1)/2)┐, N_(RBG)) + 1 bits if both  resource allocation type0 and 1 are configured.  If both resource allocation type 0 and 1 areconfigured, the MSB bit is  used to indicate resource allocation type 0or resource allocation type 1,  where the bit value of 0 indicatesresource allocation type 0 and the bit  value of 1 indicates resourceallocation type 1.  For resource allocation type 0, the N_(RBG) LSBsprovide the resource  allocation as defined in Subclause 5.1.2.2.1 of[6, TS 38.214].  For resource allocation type 1, the ┌log₂(N_(RB)^(DL,BWP) (N_(RB) ^(DL,BWP) + 1)/2)┐  LSBs provide the resourceallocation as defined in Subclause 5.1.2.2.2  of [6, TS 38.214] If“Bandwidth part indicator” field indicates a bandwidth part other thanthe active bandwidth part and if both resource allocation type 0 and 1are configured for the indicated bandwidth part, the UE assumes resourceallocation type 0 for the indicated bandwidth part if the bitwidth ofthe “Frequency domain resource assignment” field of the active bandwidthpart is smaller than the bitwidth of the “Frequency domain resourceassignment” field of the indicated bandwidth part. Time domain resourceassignment - 0, 1, 2, 3, or 4 bits as defined in Subclause 5.1.2.1 of[6, TS 38.214]. The bitwidth for this field is determined as [log₂(I)┐bits, where I is the number of entries in the higher layer parameterpdsch-TimeDomainAllocationList if the higher layer parameter isconfigured; otherwise I is the number of entries in the default table.  VRB-to-PRB mapping - 0 or 1 bit:    0 bit if only resource allocationtype 0 is configured or if    interleaved VRB-to-PRB mapping is notconfigured by high    layers;    1 bit according to Table 7.3.1.2.2-5otherwise, only applicable to    resource allocation type 1, as definedin Subclause 7.3.1.6 of    [4, TS 38.211].   PRB bundling sizeindicator - 0 bit if the higher layer parameter prb-   BundlingType isnot configured or is set to ‘static’, or 1 bit if the   higher layerparameter prb-BundlingType is set to ‘dynamic’   according to Subclause5.1.2.3 of [6, TS 38.214].   Rate matching indicator - 0, 1, or 2 bitsaccording to higher layer   parameters rateMatchPatternGroup I andrateMatchPatternGroup2,   where the MSB is used to indicaterateMatchPatternGroup1 and the   LSB is used to indicaterateMatchPatternGroup2 when there are   two groups.   ZP CSI-RStrigger - 0, 1, or 2 bits as defined in Subclause 5.1.4.2   of [6, TS38.214]. The bitwidth for this field is determined as   └log₂(n_(ZP) +1)┐ bits, where n_(ZP) is the number of aperiodic   ZP CSI-RS resourcesets configured by higher layer.  For transport block 1:    Modulationand coding scheme - 5 bits as defined in Subclause    5.1.3.1 of [6, TS38.214]    New data indicator - 1 bit    Redundancy version - 2 bits asdefined in Table 7.3.1.1.1-2  For transport block 2 (only present if maxNrofCodeWordsScheduledByDCI equals 2):    Modulation and codingscheme - 5 bits as defined in Subclause    5.1.3.1 of [6, TS 38.214]   New data indicator - 1 bit    Redundancy version - 2 bits as definedin Table 7.3.1.1.1-2    If “Bandwidth part indicator” field indicates abandwidth part other    than the active bandwidth part and the value of   maxNrofCodeWordsScheduledByDCI for the indicated bandwidth    partequals 2 and the value of maxNrofCodeWordsScheduledByDCI    for theactive bandwidth part equals 1, the UE assumes zeros are    padded wheninterpreting the “Modulation and coding scheme”,    “New dataindicator”, and “Redundancy version” fields of transport    block 2according to Subclause 12 of [5, TS38.213], and the UE    ignores the“Modulation and coding scheme”, “New data     indicator”, and“Redundancy version” fields of transport    block 2 for the indicatedbandwidth part.    HARQ process number - 4 bits    Downlink assignmentindex - number of bits as defined in the     following      4 bits ifmore than one serving cell are configured in the      DL and the higherlayer parameter pdsch-HARQ-ACK-      Codebook=dynamic, where the 2 MSBbits are the counter      DAI and the 2 LSB bits are the total DAI;     2 bits if only one serving cell is configured in the DL and the     higher layer parameter pdsch-HARQ-ACK-      Codebook=dynamic, wherethe 2 bits are the counter DAI;      0 bits otherwise.    TPC commandfor scheduled PUCCH - 2 bits as defined in    Subclause 7.2.1 of [5, TS38.213]    PUCCH resource indicator - 3 bits as defined in Subclause9.2.3    of [5, TS 38.213]    PDSCH-to-HARQ_feedback timing indicator -0, 1, 2, or 3 bits as    defined in Subclause 9.2.3 of [5, TS 38.213].The bitwidth for this    field is determined as ┌log₂(I)┐ bits, where Iis the number of    entries in the higher layer parameterdl-DataToUL-ACK.    Antenna port(s) - 4, 5, or 6 bits as defined byTables 7.3.1.2.2-    1/2/3/4, where the number of CDM groups withoutdata of    values 1 2, and 3 refers to CDM groups {0}, {0,1}, and {0,1,2}    respectively. The antenna ports {p_(0,...),p_(v−1)} shall bedetermined    according to the ordering of DMRS port(s) given by Tables   7.3.1.2.2-1/2/3/4. If a UE is configured with both   dmrs-DownlinkForPDSCH-MappingTypeA and   dmrs-DownlinkForPDSCH-MappingTypeB, the bitwidth of this    fieldequals max{x_(A), x_(B)}, where x_(A) is the “Antenna ports”    bitwidthderived according to dmrs-DownlinkForPDSCH-    MappingTypeA and x_(B) isthe “Antenna ports” bitwidth derived    according todmrs-DownlinkForPDSCH-MappingTypeB. A     number of |x_(A) − x_(B)|zeros are padded in the MSB of this field.,    if the mapping type ofthe PDSCH corresponds to the smaller    value of x_(A) and x_(B).   Transmission configuration indication - 0 bit if higher layer   parameter tci-PresentInDCI is not enabled; otherwise 3 bits    asdefined in Subclause 5.1.5 of [6, TS38.214].    If “Bandwidth partindicator” field indicates a bandwidth part other    than the activebandwidth part,     if the higher layer parameter tci-PresentInDCI isnot enabled for     the CORESET used for the PDCCH carrying the DCIformat      1_1,      the UE assumes tci-PresentInDCI is not enabled forall      CORESETs in the indicated bandwidth part;     otherwise,     the UE assumes tci-PresentInDCI is enabled for all      CORESETs inthe indicated bandwidth part.    SRS request - 2 bits as defined byTable 7.311.2-24 for UEs not    configured with supplementaryUplink inServingCellConfig in the    cell; 3 bits for UEs configured withsupplementaryUplink in    ServingCellConfig in the cell where the firstbit is the non-SUL/    SUL indicator as defined in Table 7.3.111-1 andthe second and    third bits are defined by Table 7.3.1.1.2-24. This bitfield may also    indicate the associated CSI-RS according to Subclause6.1.1.2    of [6, TS 38.214].    CBG transmission information (CBGTI) -0 bit if higher layer    parameter codeBlockGroupTransmission for PDSCHis not    configured, otherwise, 2, 4, 6, or 8 bits as defined    inSubclause 5.1.7 of [6, TS38.214], determined by the higher layer   parameters maxCodeBlockGroupsPerTransportBlock    andmaxNrofCodeWordsScheduledByDCI for the PDSCH.    CBG flushing outinformation (CBGFI) - 1 bit if higher layer    parametercodeBlockGroupFlushIndicator is configured as    “TRUE”, 0 bitotherwise.    DMRS sequence initialization - 1 bit.

Hereinafter, a method for assigning time domain resources for a datachannel in a 5G communication system will be described.

A base station may configure, for a terminal, a table relating to timedomain resource allocation information for a downlink data channel (aPDSCH) and an uplink data channel (a PUSCH) through higher layersignaling (e.g. RRC signaling). The base station may configure, for aPDSCH, a table configured by a maximum of 16 entries(maxNrofDL−Allocations=16), and may configure, for a PUSCH, a tableconfigured by a maximum of 16 entries (maxNrofUL−Allocations=16). Timedomain resource allocation (TD-RA) information may include, for example,PDCCH-to-PDSCH slot timing (a time interval expressed in the units ofslots, between a time point at which a PDCCH is received, and a timepoint at which a PDSCH scheduled by the received PDCCH is transmitted,the timing is indicated by K₀) or PDCCH-to-PUSCH slot timing (i.e. atime interval expressed in the units of slots, between a time point atwhich a PDCCH is received, and a time point at which a PUSCH scheduledby the received PDCCH is transmitted, the timing is indicated by K₂),information relating to the location of a starting symbol of a PDSCH ora PUSCH scheduled in a slot, the scheduled length, and a mapping type ofa PDSCH or a PUSCH. For example, a terminal may be notified, by a basestation, of the information shown in Tables 8 and 9, below.

TABLE 8 PDSCH-TimeDomainResourceAllocationList information elementPDSCH-TimeDomainResourceAllocationList ::= SEQUENCE(SIZE(1..maxNrofDL-Allocations)) OF  PDSCH- TimeDomainResourceAllocationPDSCH-TimeDomainResourceAllocation ::= SEQUENCE {  k0 INTEGER(0..32)OPTIONAL, ---Need S  (PDCCH-to-PDSCH timing in units of slots)mappingType ENUMERATED {typeA, typeB},  (PDSCH mapping type) startSymbolAndLength INTEGER (0..127) (Length and starting symbol of PDSCH) }

TABLE 9 PUSCH-TimeDomainResourceAllocationList information elementPUSCH-TimeDomainResourceAllocationList ::= SEQUENCE(SIZE(1..maxNrofUL-Allocations)) OF PUSCH- TimeDomainResourceAllocationPUSCH-TimeDomainResourceAllocation ::=  SEQUENCE {  k2 INTEGER(0..32)OPTIONAL, ---Need S  (PDCCH-to-PUSCH timing in units of slots) mappingType ENUMERATED {typeA, typeB},  (PUSCH mapping type) startSymbol AndLength INTEGER (0..127)  (Length and starting symbol ofPUSCH) }

The base station may notify the terminal of one of the entries of thetable relating to the time domain resource allocation informationthrough L1 signaling (e.g. DCI) (e.g. the base station may indicate oneof the entries to the terminal through a time domain resource allocationfield in DCI). The terminal may obtain time domain resource allocationinformation relating to a PDSCH or PUSCH, based on DCI received from thebase station.

Hereinafter, a method for assigning frequency domain resources for adata channel in a 5G communication system will be described.

5G supports two types of allocations including resource allocation type0 and resource allocation type 1, as a method for indicating frequencydomain resource allocation information for a downlink data channel (aPDSCH) and an uplink data channel (a PUSCH).

Resource Allocation Type 0

RB allocation information may be notified of from a base station to aterminal in a type of a bitmap for a resource block group (RBG). The RBGmay be configured by a set of consecutive VRBs, and the size P of theRBG may be determined on the basis of a value configured as a higherlayer parameter (rbg-Size), and the size of a BWP, defined in Table 10below.

TABLE 10 Nominal RBG size P BWP Size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8  73-144 8 16 145-275 16 16

A total number (N_(RBG)) of RBGs of BWP i having a size of N_(BWP,i)^(size) may be defined as below.N _(RBG)=┌(N _(BWP,i) ^(size)+(N _(BWP,i) ^(start) mod P))/P┐, where

-   -   the size of the first RBG is RBG₀ ^(size)=P−N_(BWP,i) ^(start)        mod P,    -   the size of last RBG RBG₀ ^(size)=P−N_(BWP,i) ^(start) mod P,        (N_(BWP,i) ^(start)+N_(BWP,i) ^(size)) mod P>0 and P otherwise,    -   the size of all other RBGs is P.

Each hit of a bitmap having a size of N_(RBG) bits may correspond toeach RBG. RBGs may be assigned indexes according to a sequence in whichthe frequency increases from the lowest frequency position of a BWP.With respect to N_(RBG) number of RBGs in a BWP, RBG #0 to RBG#(N_(RBG)−1) may be mapped from the MSB to the LSB of an RBG bitmap.When a particular bit value in a bitmap is 1, the terminal may determinethat an RBG corresponding to the bit value has been assigned, and when aparticular bit value in a bitmap is 0, the terminal may determine thatan RBG corresponding to the bit value has not been assigned.

Resource Allocation Type 1

RB allocation information may be notified of from a base station to aterminal by information relating to the starting position and length ofconsecutively assigned VRBs. Interleaving or non-interleaving may beadditionally applied to the consecutively assigned VRBs. A resourceallocation field of resource allocation type 1 may be configured by aresource indication value (RIV), and the RIV may be configured by thestarting point (RB_(start)) of a VRB and the length (L_(RBs)) ofconsecutively assigned RBs. More specifically, an RIV of a BWP having asize of N_(BWP) ^(size) may be defined as follows.

-   -   if (L_(RBs)−1)≤└N_(BWP) ^(size)/2┘ then        RIV=N _(BWP) ^(size)(L _(RBs)−1)+RB_(start)        else        RIV=N _(BWP) ^(size)(N _(BWP) ^(size) −L _(RBs)+1)+(N _(BWP)        ^(size)−1−RB_(start))    -   where L_(RBs)≥1 and shall not exceed N_(BWP) ^(size)−RB_(start).

The base station may configure, for the terminal, a resource allocationtype through higher layer signaling (e.g. a higher layer parameterresourceAllocation may be configured to be one value amongresourceAllocationType0, resourceAllocationType1, or dynamicSwitch). Ifboth resource allocation types 0 and 1 are configured for the terminal(or in the same way, the higher layer parameter resourceAllocation isconfigured to be dynamicSwitch), a bit corresponding to the MSB in aresource allocation indication field in a DCI format indicatingscheduling may indicate resource allocation type 0 or 1, resourceallocation information may be indicated through the remaining bitsexcept for the bit corresponding to the MSB on the basis of theindicated resource allocation type, and the terminal may interpretresource allocation field information of the DCI field, based on theindications. If one of resource allocation type 0 or 1 is configured forthe terminal (or in the same way, the higher layer parameterresourceAllocation is configured to be resourceAllocationType0 orresourceAllocation Type1), a resource allocation indication field in aDCI format indicating scheduling may indicate resource allocationinformation, based on the configured resource allocation type, and theterminal may interpret resource allocation field information of the DCIfield, based on the indication.

Hereinafter, a downlink control channel of a 5G communication systemwill be described in detail with reference to the drawings.

FIG. 4 illustrates an example of a CORESET on which a downlink controlchannel is transmitted in a 5G wireless communication system, accordingto an embodiment. FIG. 4 shows an example in which a UE BWP 410 of aterminal is configured along a frequency axis, and CORESET #1 401 andCORESET #2 402 are configured in one slot 420 along a time axis. TheCORESETs 401 and 402 may be configured on a particular frequencyresource 403 in the entire terminal BWP 410 along the frequency axis.CORESET #1 401 and CORESET #2 402 may be configured by one OFDM symbolor multiple OFDM symbols along the time axis, and the configured OFDMsymbol or symbols may be defined as a CORESET duration 404. Withreference to the example illustrated in FIG. 4, CORESET #1 401 isconfigured to have a CORESET duration of two symbols, and CORESET #2 402is configured to have a CORESET duration of one symbol.

A CORESET in 5G, described above, may be configured for a terminal by abase station through higher layer signaling (e.g. system information,MIB, and RRC signaling). Configuring a CORESET for a terminal meansproviding of information such as a CORESET identity, the frequencylocation of the CORESET, or the symbol length of the CORESET. Forexample, the configuration may include the information shown in Table11, below.

TABLE 11 ControlResourceSet ::= SEQUENCE {  -- Corresponds to L1parameter ′CORESET-ID′ controlResourceSetId ControlResourceSetid,(CORESET identifier (Identity)) frequencyDomainResources  BIT STRING(SIZE (45)), (Frequency axis resource allocation information)  durationINTEGER (1.. maxCoReSetDuration),  (Time axis resource allocationinformation)  cce-REG-MappingType  CHOICE {  (CCE-to-REG mapping scheme)  interleaved SEQUENCE {     reg-BundleSize  ENUMERATED {n2, n3, n6},   (REG bundle size)     precoderGranularity  ENUMERATED{sameAsREG-bundle, allContiguousRBs},     interleaverSize  ENUMERATED{n2, n3, n6}     (Interleaver size)     shiftIndex INTEGER(0..maxNrofPhysicalResourceBlocks−1)    OPTIONAL    (Interleaver shift)    },  nonInterleaved  NULL  },  tci-StatesPDCCH SEQUENCE(SIZE (1..maxNrofTCI-StatesPDCCH)) OF TCI-StateId OPTIONAL, (QCL configuration information)  tci-PresentInDCI ENUMERATED {enabled}OPTIONAL, -- Need S }

In Table 11, tci-StatesPDCCH (simply, referred to as a transmissionconfiguration indication (TCI) state) configuration information mayinclude information on the index or indexes of one or multiple SS/PBCHblocks having a quasi-co-located (QCL) relationship with a DMRStransmitted on a corresponding CORESET, or information on the index of achannel state information reference signal (CSI-RS).

FIG. 5 illustrates an example of a basic unit of time and frequencyresources configuring a downlink control channel, which can be used in5G, according to an embodiment. As illustrated in FIG. 5, a basic unitof time and frequency resources configuring a control channel may benamed a resource element group (REG) 503, and the REG 503 may be definedas one OFDM symbol 501 in a time axis and one PRB 502 in a frequencyaxis, that is, may be defined as 12 subcarriers. A base station connectsand attaches REGs 503 described above to each other to configure adownlink control channel assignment unit.

As illustrated in FIG. 5, if a basic unit for the assignment of adownlink control channel in 5G is a control channel element (CCE) 504,one CCE 504 may be configured by a plurality of the REGs 503. Forexample, the REG 503 illustrated in FIG. 5 may be configured by 12 REs,and if one CCE 504 is configured by six REGs 503, the one CCE 504 may beconfigured by 72 REs. If a downlink CORESET is configured, the resourceset may be configured by a plurality of CCEs 504, and a particulardownlink control channel may be transmitted after being mapped to oneCCE 504 or multiple CCEs 504 according to an aggregation level (AL) inthe CORESET. CCEs 504 in a CORESET are distinguished by numbers, and thenumbers of the CCEs 504 may be assigned according to a logical mappingscheme.

The basic unit of a downlink control channel, illustrated in FIG. 5,that is, an REG 503 may include REs to which DCI is mapped and a regionto which a DMRS 505, which is a reference signal for decoding the REs,is mapped. As illustrated in FIG. 5, three DMRSs 505 may be transmittedin one REG 503. The number of CCEs required for transmitting a PDCCH maybe 1, 2, 4, 8, and 16 according to ALs, and different numbers of CCEsmay be used to implement the link adaptation of the downlink controlchannel. For example, if AL=L, one downlink control channel may betransmitted through L number of CCEs. A terminal is required to detect asignal in the state where the terminal does not know informationrelating to a downlink control channel, and a search space indicating aset of CCEs is defined for blind decoding. A search space is a set ofdownlink control channel candidates configured by CCEs to which theterminal is required to attempt to decode at a given aggregation level.Since there are various aggregation levels grouping 1, 2, 4, 8, and 16CCEs into one, respectively, the terminal may have a plurality of searchspaces. A search space set may be defined to be a set of search spacesat all the configured aggregation levels.

Search spaces may be classified into a common search space and aterminal (UE)-specific search space. A particular group of terminals orall terminals may investigate a common search space for a PDCCH toreceive cell-common control information such as a paging message ordynamic scheduling for system information. The terminals may investigatea common search space for a PDCCH to receive PDSCH scheduling assignmentinformation for transmission of a SIB including cell operatorinformation. In the case of a common search space, a particular group ofterminals or all terminals are required to receive a PDCCH, and thus thecommon search space may be defined to be a pre-promised set of CCEs. Theterminals may investigate a terminal-specific search space for a PDCCHto receive scheduling assignment information for a terminal-specificPDSCH or PUSCH. A terminal-specific search space may be definedterminal-specifically by using the identity of a terminal and thefunctions of various system parameters.

In 5G, a parameter for a search space for a PDCCH may be configured fora terminal by a base station through higher layer signaling (e.g. SIB,MIB, and RRC signaling). For example, the base station may configure,for the terminal, the number of PDCCH candidates at each aggregationlevel L, a monitoring period for a search space, a monitoring occasionexpressed in the units of symbols in a slot of a search space, a searchspace type (common search space or terminal-specific search space), acombination of an RNTI and a DCI format to be monitored in acorresponding search space, and the index of a CORESET in which a searchspace is to be monitored. For example, a parameter relating to a searchspace for a PDCCH may include the information shown in Table 12, below.

TABLE 12 SearchSpace ::= SEQUENCE {  Identity of the search space.SearchSpaceId = 0 identifies the SearchSpace configured via PBCH (MIB)or ServingCellConfigCommon.  searchSpaceId SearchSpaceId,  (Search spaceidentifier)  controlResourceSetId ControlResourceSetId,  (CORESETidentifier)  monitoringSlotPeriodicityAndOffset CHOICE {  (Monitoringslot level period)   sll NULL,   sl2 INTEGER (0..1),   sl4 INTEGER(0..3),   sl5 INTEGER (0..4),   sl8 INTEGER (0..7),   sl10 INTEGER(0..9),   sll6 INTEGER (0..15),   sl20 INTEGER (0..19)  } OPTIONAL, duration(Monitoring length) INTEGER (2..2559) monitoringSymbolsWithinSlot BIT STRING (SIZE (14)) OPTIONAL, (Monitoring symbols in slot)  nrofCandidates SEQUENCE {  (The number ofPDCCH candidates for each aggregation level)   aggregationLevel1ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},   aggregationLevel2ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},   aggregationLevel4ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},   aggregationLevel8ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},   aggregationLevel16ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}  }  searchSpaceType CHOICE { (Search space type)    Configures this search space as common searchspace (CSS) and DCI formats to monitor.    common SEQUENCE {   (Commonsearch space)    }    ue-Specific SEQUENCE {   (Terminal-specific searchspace)     Indicates whether the UE monitors in this USS for DCI formats0-0 and 1-0 or for formats 0-1 and 1-1.     formats ENUMERATED{formats0- 0-And-1-0, formats0-1-And-1-1},     ...    }

The base station may configure one search space set or multiple searchspace sets for the terminal according to the configuration information.The base station may configure search space set 1 and search space set 2for the terminal. In search space set 1, DCI format A scrambled byX-RNTI may be configured to be monitored in a common search space, andin search space set 2, DCI format B scrambled by Y-RNTI may beconfigured to be monitored in a terminal-specific search space.

According to the configuration information, one search space set ormultiple search space sets may exist in a common search space or aterminal-specific search space. For example, search space set #1 andsearch space set #2 may be configured to be common search spaces, andsearch space set #3 and search space set #4 may be configured to beterminal-specific search spaces.

In a common search space, the following combinations of a DCI format andan RNTI, as shown below, may be monitored.

-   -   DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI,        SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI    -   DCI format 2_0 with CRC scrambled by SFI-RNTI    -   DCI format 2_1 with CRC scrambled by INT-RNTI    -   DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI,        TPC-PUCCH-RNTI    -   DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

In a terminal-specific search space, the following combinations of a DCIformat and an RNTI, as shown below, may be monitored.

-   -   DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI,        TC-RNTI    -   DCI format 1_0/1_1 with CRC scrambled by C-RNTI, CS-RNTI,        TC-RNTI

The described types of RNTIs may be characterized by the followingdefinitions and purposes, as shown below.

-   -   C-RNTI: for the purpose of scheduling a terminal-specific PDSCH.    -   Temporary C-RNTI (TC-RNTI): for the purpose of scheduling a        terminal-specific PDSCH.    -   Configured scheduling RNTI (CS-RNTI): for the purpose of        scheduling semi-statically configured terminal-specific PDSCH.    -   Random access RNTI (RA-RNTI): for the purpose of scheduling a        PDSCH in a random access stage.    -   Paging RNTI (P-RNTI): for the purpose of scheduling a PDSCH on        which paging is transmitted.    -   System information RNTI (SI-RNTI): for the purpose of scheduling        a PDSCH on which system information is transmitted.    -   Interruption RNTI (INT-RNTI): for the purpose of notifying of        whether a PDSCH is punctured.    -   TPC for PUSCH RNTI (TPC-PUSCH-RNTI): for the purpose of        indicating a power control command for a PUSCH.    -   TPC for PUCCH RNTI (TPC-PUCCH-RNTI): for the purpose of        indicating a power control command for a PUCCH.    -   TPC for SRS RNTI (TPC-SRS-RNTI): for the purpose of indicating a        power control command for an SRS.

The described DCI formats may be characterized by the following usagesshown in Table 13, below.

TABLE 13 DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s)where UE may assume no transmission is intended for the UE 2 2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs

In 5G, a search space for aggregation level L in CORESET p and searchspace set s may be expressed as shown in Equation (1), below.

$\begin{matrix}{{L \cdot \left\{ {\left( {Y_{p,n_{s,f}^{\mu}} + \left\lfloor \frac{m_{s,n_{CI}} \cdot n_{{CCE},p}}{L \cdot M_{p,s,{{ma}\; x}}^{(L)}} \right\rfloor + n_{CI}} \right){mod}\left\lfloor {N_{{CCE},p}/L} \right\rfloor} \right\}} + i} & (1)\end{matrix}$

The variables shown above in Equation (1) are defined as follows:

-   -   L: aggregation level    -   n_(CI): carrier index    -   N_(CCE,p): the total number of CCEs existing in CORESET p    -   n^(μ) _(s,f): slot index    -   M^((L)) _(p,s,max): the number of PDCCH candidates at        aggregation level L    -   m_(snCl)=0, . . . , M^((L)) _(p,s,max)−1: the indexes of PDCCH        candidates at aggregation level L    -   i=0, . . . , L−1    -   Y_(p,n) _(s,f) _(μ) =(A_(p)·Y_(p,n) _(s,f) _(μ) ⁻¹) mod D,        Y_(p,−1)=n_(RNTI)≠0, A₀=39827, A₁=39829, A₂=39839, D=65537    -   n_(RNTI): terminal identifier

In a case of a common search space, Y_(p,n^(μ) _(s,f)) may be 0.

In a case of a terminal-specific search space, Y_(p,n^(μ) _(s,f)) may bechanged according to a time index and the identity (C-RNTI or IDconfigured for a terminal by a base station) of a terminal.

In 5G, a plurality of search space sets may be configured by differentparameters (e.g. the parameters in Table 10). Therefore, a set of searchspace sets monitored by a terminal may be changed at every time point.For example, if search space set #1 is configured to have an X-slotperiod, search space set #2 is configured to have an Y-slot period, andX is different from Y, a terminal may monitor both search space set #1and search space set #2 in a particular slot, and may monitor one ofsearch space set #1 and search space set #2 in a particular slot.

If a plurality of search space sets are configured for a terminal, theconditions below may be considered in a method for determining a searchspace set required to be monitored by the terminal.

Condition 1: Limitation of the Maximum Number of PDCCH Candidates

The number of PDCCH candidates that can be monitored per slot does notexceed M^(μ). M^(μ) may be defined to be the maximum number of PDCCHcandidates per slot in a cell configured to have subcarrier spacing of15·2^(μ) KHz, and may be defined as shown in Table 14, below.

TABLE 14 Maximum number of PDCCH candidates per μ slot and per servingcell (M^(μ)) 0 44 1 36 2 22 3 20

Condition 2: Limitation of the Maximum Number of CCEs

The number of CCEs configuring an entire search space (herein, theentire search space denotes all CCE sets corresponding to a union regionof a plurality of search space sets) per slot does not exceed C^(μ).C^(μ) may be defined to be the maximum number of CCEs per slot in a cellconfigured to have subcarrier spacing of 15·2^(μ) kHz, and may bedefined as shown in Table 15, below.

TABLE 15 μ Maximum number of CCEs per slot and per serving cell (C^(μ))0 56 1 56 2 48 3 32

For convenience of explanation, condition A is defined as a situationsatisfying both conditions 1 and 2 at a particular time point.Therefore, non-satisfaction of condition A may imply non-satisfaction ofat least one of conditions 1 and 2.

A case which does not satisfy condition A at a particular time point mayoccur according to a configuration of search space sets by the basestation. If condition A is not satisfied at a particular time point, theterminal may select and monitor only a part of search space setsconfigured to satisfy condition A at the time point, and the basestation may transmit a PDCCH through the selected part of search spacesets.

A method of selecting some search spaces of all configured search spacesets is described below.

In a case where condition A relating to a PDCCH is not satisfied at aparticular time point (slot), a terminal (a base station) may select asearch space set configured to have a search space type of a commonsearch space among search space sets existing at the time point inpreference to a search space set configured to have a search space typeof a terminal-specific search space.

If all search space sets configured as a common search space areselected (i.e. if condition A is satisfied even after all search spacesconfigured as a common search space are selected), the terminal (or thebase station) may select search space sets configured as aterminal-specific search space. If there are a plurality of search spacesets configured as a terminal-specific search space, the smaller theindex of a search space set, the higher the priority of the search spaceset. Terminal-specific search space sets may be selected within a rangeof satisfying condition A in consideration of the priorities.

FIG. 6 illustrates discontinuous reception (DRX) according to anembodiment.

Discontinuous reception (DRX) is an operation in which a terminal usinga service discontinuously receives data in an RRC-connected state inwhich a wireless link is configured between a base station and theterminal. In a case where DRX is applied, the terminal may turn on areceiver at a particular time point to monitor a control channel. Ifthere is no data received for a predetermined period, the terminal mayturn off the receiver to reduce the power consumption of the terminal. ADRX operation may be controlled by a media access control (MAC) layerdevice, based on various parameters and timers.

Referring to FIG. 6, an active time 605 is a time interval for which theterminal wakes up at DRX periods and monitors a PDCCH. The active time605 may be defined based on the following parameters.

-   -   drx-onDurationTimer, drx-InactivityTimer,        drx-RetransmissionTimerDL, drx-RetransmissionTimerUL or        ra-ContentionResolutionTimer is running;    -   a Scheduling Request is sent on PUCCH and is pending; or    -   a PDCCH indicating a new transmission addressed to the C-RNTI of        the MAC entity has not been received after successful reception        of a random access response for the random access preamble not        selected by the MAC entity among the contention-based random        access preamble.

A drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL,drx-RetransmissionTimerUL, and ra-ContentionResolutionTimer are timers,the values of which are configured by the base station, and function toconfigure the terminal to monitor a PDCCH in a situation satisfying apredetermined condition.

A drx-onDurationTimer 615 is a parameter for configuring a minimum timeinterval in which the terminal is awake in a DRX cycle. Adrx-InactivityTimer 620 is a parameter for configuring a time intervalin which the terminal is additionally awake in a case 630 where a PDCCHindicating new uplink transmission or downlink transmission is received.A drx-RetransmissionTimerDL is a parameter for configuring a maximumtime interval in which the terminal is awake to receive downlinkretransmission in a downlink HARQ process. A drx-RetransmissionTimerULis a parameter for configuring a maximum time interval in which theterminal is awake to receive a grant for uplink retransmission in anuplink process. A drx-onDurationTimer, drx-InactivityTimer,drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL may beconfigured by a time, the number of subframes, or the number of slots.An ra-ContentionResolutionTimer is a parameter for monitoring a PDCCH ina random access process.

An inactive time 610 is a time interval configured not to monitor orreceive a PDCCH in the DRX operation. The time interval remaining aftersubtracting the active time 605 from the entire time interval in whichthe DRX operation is performed may be the inactive time 610. If theterminal does not monitor a PDCCH during the active time 605, theterminal may enter a sleep or inactive state to reduce powerconsumption.

A DRX cycle denotes a period according to which the terminal wakes upand monitors a PDCCH. That is, a DRX cycle denotes a time intervalbetween monitoring of a PDCCH by the terminal and monitoring of a nextPDCCH, or an on-duration occurrence period. There are two types of DRXcycles which may be applied, a short DRX cycle and a long DRX cycle.

A long DRX cycle 625 is a long cycle among two types of DRX cyclesconfigured for the terminal. While the terminal is operating accordingto a long DRX cycle, the terminal restarts the drx-onDurationTimer 615at a time point after passage of the long DRX cycle 625 from a startpoint (e.g. starting symbol) of the drx-onDurationTimer 615. If theterminal is operated according to the long DRX cycle 625, the terminalmay start the drx-onDurationTimer 615 in a slot after passage of adrx-SlotOffset in a subframe satisfying Equation (2), below. Thedrx-SlotOffset implies a delay before the drx-onDurationTimer 615 isstarted. The drx-SlotOffset may be configured by a time, or the numberof slots.[(SFN×10)+subframe number]modulo(drx-LongCycle)=drx-StartOffset  (2)

A drx-LongCycleStartOffset may include the long DRX cycle 625 and adrx-StartOffset, and may be used to define a subframe in which the longDRX cycle 625 is to start. The drx-LongCycleStartOffset may beconfigured by a time, the number of slots, or the number of slots.

The short DRX cycle is the short cycle among two DRX cycles defined fora terminal. If there occurs a predetermined event, for example, a casewhere a PDCCH indicating a new uplink transmission or downlinktransmission is received 630, in the active time 605 while the terminalis being operated according to the long DRX cycle 625, the terminal maystart or restart the drx-InactivityTimer 620. If the drx-InactivityTimer620 is expired or a DRX command MAC CE is received, the terminal may beoperated according to a short DRX cycle.

As illustrated in FIG. 6, the terminal may start a drx-ShortCycleTimerat a time point when the prior drx-onDurationTimer 615 ordrx-InactivityTimer 620 is expired, and may be operated according to ashort DRX cycle until the drx-ShortCycleTimer is expired. If a PDCCHindicating a new uplink transmission or downlink transmission isreceived 630, the terminal may extend the active time 605 or delay thearrival of the inactive time 610 while expecting that there will be alsoadditional uplink transmission or downlink transmission. While theterminal is operated according to a short DRX cycle, the terminalrestarts the drx-onDurationTimer 615 at a time point after passage of ashort DRX cycle from the starting point of a prior on-duration.Thereafter, when the drx-ShortCycleTimer is expired, the terminal againstarts to operate according to the long DRX cycle 625.

If the terminal is operated according to a short DRX cycle, the terminalmay start the drx-onDurationTimer 615 after passage of a drx-SlotOffsetin a subframe satisfying Equation (3), below. The drx-SlotOffset impliesa delay before the drx-onDurationTimer 615 is started. Thedrx-SlotOffset may be configured by a time or the number of slots.[(SFN×10)+subframe number]modulo(drx-ShortCycle)=(drx-StartOffset)modulo(drx-ShortCycle)  (3)

The drx-ShortCycle and the drx-StartOffset may be used to define asubframe in which a short DRX cycle is to start. The drx-ShortCycle andthe drx-StartOffset may be configured by a time or the number of slots.

In the above description, a DRX operation has been explained withreference to FIG. 6. According to an embodiment, a terminal can reducepower consumption by performing a DRX operation. However, even if aterminal performs a DRX operation, the terminal does not always receivea PDCCH related to the terminal in the active time 605. Therefore, anembodiment may provide a signal for controlling the operation of aterminal in order to more efficiently save the power of the terminal.

Hereinafter, a carrier aggregation and scheduling method for a 5Gcommunication system will be described.

A terminal may connect to a primary cell through an initial access, anda base station may additionally configure one or multiple secondarycells for the terminal. The terminal may perform communication throughserving cells including the primary cell and secondary cells configuredby the base station.

The base station may additionally configure whether cross-carrierscheduling is performed for cells configured for the terminal. Forconvenience of explanation, in a case where cross-carrier scheduling isconfigured, a cell performing scheduling (i.e. a cell receiving downlinkcontrol information corresponding to a downlink assignment or an uplinkgrant) is collectively referred to as a first cell, and a cell which isscheduled (i.e. a cell on which downlink or uplink data is actuallyscheduled on the basis of downlink control information, and is thentransmitted or received) is named a second cell. If cross-carrierscheduling for particular cell A (a cell which is scheduled, i.e., ascheduled cell) is configured for the terminal by the base station(wherein cell A corresponds to a second cell), the terminal may notperform PDCCH monitoring on cell A and cell B, which is indicated by thecross-carrier scheduling, that is, a scheduling cell (wherein cell Bcorresponds to a first cell). The base station may configure, for theterminal, information relating to a first cell scheduling for a secondcell (e.g. the cell index of a cell corresponding to the first cell),and a carrier indicator field (CIF) value for the second cell in orderto configure cross-carrier scheduling for the terminal. For example, theconfiguration information shown below in Table 16 may be communicated tothe terminal from the base station through higher layer signaling (e.g.RRC signaling).

TABLE 16 CrossCarrierSchedulingConfig ::=  SEQUENCE { schedulingCellInfo  CHOICE { own (self-carrier scheduling)   SEQUENCE { No cross carrierscheduling cif-Presence   BOOLEAN }, other (cross-carrier scheduling)SEQUENCE { Cross carrier scheduling schedulingCellId   ServCellIndex,(The cell index of a scheduling cell) cif-InSchedulingCell   INTEGER(1..7) (CIF value) } }, ... }

The terminal may monitor a PDCCH for a cell configured by thecross-carrier scheduling, on a cell corresponding to the first cell. Theterminal may determine the index of a cell scheduled by received DCIfrom a carrier indicator field value in a DCI format scheduling data. Onthe basis of the index, the terminal may transmit or receive data on thecell indicated by a carrier indicator.

The scheduled cell (cell A) and the scheduling cell (cell B) may beconfigured by different numerologies. Each of the numerologies mayinclude subcarrier spacing and a cyclic prefix. In a case where thenumerologies of cells A and B are different, when a PDCCH of cell Bschedules a PDSCH of cell A, a minimum scheduling offset as describedbelow may be additionally considered between the PDCCH and the PDSCH.

Cross-Carrier Scheduling Method

When the subcarrier spacing (μ_(B)) of cell B is smaller than thesubcarrier spacing (μ_(A)) of cell A, a PDSCH may be scheduled from aPDSCH slot next to a slot after passage of X symbols from the lastsymbol of a PDCCH received in cell B. X may vary according to μ_(B),when μ_(B) equals to 15 kHz, X may be defined as 4 symbols, when μ_(B)equals 30 kHz, X may be defined as 4 symbols, and when μ_(B) equals 60kHz, or X may be defined as 8 symbols.

When the subcarrier spacing (μ_(B)) of cell B is larger than thesubcarrier spacing (μ_(A)) of cell A, a PDSCH may be scheduled from atime point corresponding to a slot after passage of X symbols from thelast symbol of a PDCCH received in cell B. X may vary according toμ_(B), when μ_(B) equals to 30 kHz, X may be defined as 4 symbols, whenμ_(B) equals to 60 kHz, X may be defined as 8 symbols, and when μ_(B)equals 120 kHz, X may be defined as 12 symbols.

Hereinafter, higher layer signaling may be signaling corresponding to atleast one of the following signalings below, or a combination of one ormore thereof.

-   -   MIB    -   SIB or SIB X (X=1, 2, . . . )    -   RRC    -   MAC control element CE    -   UE capability reporting

In addition, L1 signaling may be signaling corresponding to at least oneof the physical layer channels or signaling methods below, or acombination of one or more thereof.

-   -   PDCCH    -   DCI    -   UE-specific DCI    -   Group common DCI    -   Common DCI    -   Scheduling DCI (e.g. DCI used for scheduling downlink or uplink        data)    -   Non-scheduling DCI (e.g. DCI for not scheduling downlink or        uplink data)    -   PUCCH    -   uplink control information (UCI)

In order to reduce the power consumption of a terminal, 5G may support aparticular serving cell (e.g. a secondary cell) to be in a dormantstate, or may support the serving cell to be operated in a dormant BWP.A serving cell being operated in a dormant BWP may imply that thedormant BWP is activated for the serving cell. The dormant BWP maycorrespond to a BWP which has no configuration for a PDCCH or isindicated as a dormant BWP, among random BWPs configured for theterminal. In a case where a secondary cell is in a dormant state, or adormant BWP is activated in a secondary cell, the terminal may notperform PDCCH monitoring on the cell (or intermittently monitor aPDCCH), and may consistently perform an operation, such as a channelstate measurement (CSI measurement), an adaptive gain control (AGC), ora beam management. Accordingly, the terminal can largely reduce thepower consumed to maintain a cell, which is not currently used butactivated.

A terminal may receive, through L1 signaling and from a base station, anindicator indicating a dormant state of a secondary cell, or anindicator indicating a change to a dormant BWP (referred to as adormancy indicator).

A dormancy indicator for a secondary cell as described above may beconfigured based on the following parameters.

-   -   The dormancy indicator may be configured by a bitmap having N        bits, and each of the bits of the bitmap may correspond to one        secondary cell or one secondary cell group including multiple        secondary cells.    -   The size of the bitmap may be the same as the number of        configured secondary cells or secondary cell groups.    -   If 0 is indicated as one bit value of a bitmap, the terminal may        switch, into a dormant state, the cell state of a secondary cell        indicated by the bit, or the cell states of all secondary cells        of a secondary cell group indicated thereby (or may activate a        dormant BWP configured for the cell(s)).    -   If 1 is indicated as one bit value of a bitmap, the terminal may        switch, into an active state, the cell state of a secondary cell        indicated by the bit, or the cell states of all secondary cells        of a secondary cell group indicated thereby (or may activate        another bandwidth rather than a dormant BWP configured for the        cell(s), wherein another BWP rather than the dormant BWP, which        is to be activated in response to 1 being indicated as a bit        value, may be configured for the terminal through higher layer        signaling from the base station).

The terminal may receive the above dormancy indicator through aparticular DCI format. That is, the dormancy indicator may betransferred to the terminal through a particular DCI format. Theparticular DCI format may correspond to a DCI format which does notinclude scheduling information for data (non-scheduling DCI, e.g. thismay correspond to DCI format 2_X (X=0, 1, 2, . . . ); a DCI format whichcan include scheduling information for data (scheduling DCI withscheduling information, e.g. this may correspond to DCI format 0_X orDCI format 1_X (X=0, 1, 2, . . . ); or a DCI format which can includescheduling information for data, but does not actually includescheduling information (scheduling DCI without scheduling information,e.g. this may correspond to DCI format 0_X or DCI format 1_x (X=0, 1, 2,. . . ). A DCI format indicating a dormancy indicator for a secondarycell, described above, may be received in a primary cell.

A DCI format including a dormancy indicator field may be configured forthe terminal from the base station. In addition, a search space setconfigured for monitoring a PDCCH for detecting the DCI format includingthe dormancy indicator field may be configured for the terminal. Theterminal may monitor a PDCCH in the configured search space to detectthe DCI format including the dormancy indicator, and may change the BWPor the state of the secondary cell according to the contents of thedormancy indicator field obtained from the DCI format.

When a particular field value of a DCI format satisfies a particularcondition A, the terminal may assume that the DCI format is a DCI formatincluding a dormancy indicator field. For example, if a search space setis configured for the terminal to monitor a PDCCH for a particular DCIformat, and a value of a frequency domain resource allocation fieldthereof satisfies particular condition A, the terminal may consider theDCI format as a DCI format including a dormancy indicator field.Condition A may correspond to at least one of the following eight (8)conditions below, or a combination of one or more thereof.

Condition 1

A resource allocation type (resourceAllocation) is configured to be type0 (resourceAllocationType0), and each of the frequency domain resourceallocation field values in a corresponding DCI format are 0,

the resource allocation type (resourceAllocation) is configured to betype 1 (resourceAllocationType1), and each of the frequency domainresource allocation field values in the DCI format are 1, or

the resource allocation type (resourceAllocation) is configured to bedynamicSwitch (or configured equally to be both type 0 and type 1), andeach of the frequency domain resource allocation field values in the DCIformat are 0 or 1.

Condition 2

The resource allocation type (resourceAllocation) is configured to betype 0 (resourceAllocationType0), or the resource allocation type(resourceAllocation) is configured to be dynamicSwitch (or configuredequally to be both type 0 and type 1), and each of the frequency domainresource allocation field values in the DCI format are 0, or

the resource allocation type (resourceAllocation) is configured to betype 1 (resourceAllocationType1), and each of the frequency domainresource allocation field values in the DCI format are 1.

Condition 3

The resource allocation type (resourceAllocation) is configured to betype 0 (resourceAllocationType0), and each of the frequency domainresource allocation field values in the DCI format are 0, or

the resource allocation type (resourceAllocation) is configured to betype 1 (resourceAllocationType1), or the resource allocation type(resourceAllocation) is configured to be dynamicSwitch (or configuredequally to be both type 0 and 1), and each of the frequency domainresource allocation field values in the DCI format are 1.

Condition 4

Each of the carrier indicator field values are 0.

Condition 5

A value of the carrier indicator field indicates the index of a cellconfigured for monitoring the DCI format.

Condition 6

A value of the carrier indicator field indicates the index of a primarycell or a secondary primary cell.

Condition 7

A DCI format identifier value is 1.

Condition 8

Each of the BWP indicator field values are 0.

In a case where a DCI format satisfies particular condition B, theterminal may determine the above condition A to determine whether theDCI format is a DCI format including a dormancy indicator. Condition Bmay correspond to at least one of the following two (2) conditions,below.

Condition 1

A corresponding DCI format may include a CRC scrambled by at least oneof a C-RNTI or an MCS-C-RNTI.

Condition 2

The DCI format may include a CRC scrambled by at least one of a C-RNTIor an MCS-C-RNTI, and the terminal may not check condition A when theCRC of the DCI format is scrambled by a CS-RNTI.

The above DCI format may correspond to a DCI format (e.g. DCI format 1_0or 1_1) scheduling a PDSCH. Alternatively, in the same way, the DCIformat may correspond to a DCI format having a DCI format identifierfield value of 1.

If the above DCI format is determined by the terminal to be a DCI formatincluding a dormancy indicator, the terminal may consider that acombination of the following fields in the DCI format is a dormancyindicator field, the fields including a modulation and coding scheme, anew data indicator, a redundancy version, a HARQ process number, antennaport(s), and a DMRS sequence initialization.

If the above DCI format is determined by the terminal to be a DCI formatincluding a dormancy indicator, the terminal may neglect a BWP indicatorfield value in the DCI format.

If the above DCI format is determined by the terminal to be a DCI formatincluding a dormancy indicator, the terminal may change a BWP, based ona BWP indicator field value in the DCI format. The terminal may notperform any transmission or reception during a time interval from thethird symbols of a slot receiving a PDCCH including the DCI to thestarting point of a slot corresponding to a latency time interval(T_(BWP)) required for the change of the BWP. For example, if theterminal receives a DCI indicating a change of a BWP in slot n, andcorresponding T_(BWP) is equal to K, the terminal may not perform anytransmission or reception during a time interval from the third symbolof slot n to the symbol before slot n+K (i.e. the last symbol of slotn+K−1). T_(BWP) may correspond to a supportable value reported by theterminal to the base station according to the capability of theterminal.

In addition, various features described above may be carried out incombination (i.e., one after another or in parallel).

FIG. 7 illustrates a terminal operation, according to an embodiment.

In step 701, a terminal receives configuration information of asecondary cell. The configuration information of the secondary cell mayinclude configuration information defining a group for one or multiplecells, or configuration information of a dormant BWP for each secondarycell.

In step 702, the terminal receives configuration information of a PDCCHand a DCI format. The terminal may receive configuration information ofa CORESET and configuration information of a search space, as a part ofthe PDCCH configuration information. The terminal may monitor the PDCCHon the basis of the search space configuration information, and detect aparticular DCI format.

In step 703, the terminal determines whether the detected DCI formatsatisfies a particular condition. According to an embodiment, theparticular condition may correspond to whether a dormancy indicatorfield is configured in the detected DCI format. According to anotherembodiment, the particular condition may correspond to a combination ofat least some of the various conditions described above.

When it is determined in step 703 that the detected DCI format does notsatisfy the particular condition, the terminal performs a first DCIfield interpretation operation of the received DCI format, in step 704.The first DCI field interpretation operation may imply obtaininginformation according to the content of an existing field of thereceived DCI format. The terminal may perform a series of operations onthe basis of control information of the received DCI format.

When it is determined in step 703 that the detected DCI format satisfiesthe particular condition, the terminal performs a second DCI fieldinterpretation operation of the received DCI format, in step 705. Thesecond DCI field interpretation operation may imply obtaining thecontent of a dormancy indicator field from the received DCI format.According to an embodiment, the terminal may obtain the content of thedormancy indicator field from the dormancy indicator field configured tobe separate from the existing field. According to another embodiment,the terminal may reinterpret partial content of the existing field,consider the reinterpreted content as obtained from a dormancy indicatorfield, and obtain the content of the dormancy indicator field from thereinterpreted content.

In step 706, the terminal changes a dormant state of the secondary cell,based on the obtained dormancy indicator field content of secondarycell. The operation of changing the dormant state of the secondary cellmay be an operation of switching the cell state into the dormant stateaccording to the content of the dormancy indicator field (or activatinga dormant BWP configured for the cell), or an operation of switching thecell state into an active state (or activating a different BWP ratherthan a dormant BWP configured for the cell).

FIG. 8 is a block diagram showing a structure of a terminal, accordingto an embodiment.

Referring to FIG. 8, a terminal includes a transceiver 801, a memory802, and a processor 803. The elements of the terminal are not limitedto the above example and may include more or fewer elements than theabove elements. In addition, at least one or all of the transceiver 801,the memory 802, and the processor 803 may be implemented into a singlechip.

The transceiver 801 may transmit or receive a signal to or from a basestation. The signal may include control information and data. To thisend, the transceiver 801 may include a radio frequency (RF) transmitterthat up-converts and amplifies a frequency of a transmitted signal andan RF receiver that low-noise amplifies a received signal anddown-converts the frequency. In addition, the transceiver 801 mayreceive a signal through a wireless channel and output the signal to theprocessor 803, and may transmit a signal output from the processor 803,through a wireless channel.

The memory 802 may store a program and data required for an operation ofthe terminal. In addition, the memory 802 may store control informationor data included in a signal transmitted or received by the terminal.The memory 802 may be configured by a storage medium such as a read onlymemory (ROM), a random access memory (RAM), a hard disk, a compact disc(CD)-ROM, a digital versatile disc (DVD), or a combination of storagemediums. In addition, the memory 602 may include a plurality ofmemories. The memory 802 may store a program for executing an operationfor power saving of the terminal.

The processor 803 may control a series of processes in which theterminal may operate according to embodiments described above. Theprocessor 803 may execute the program stored in the memory 802, so as tocontrol the terminal to receive configuration information of a DCIformat including a dormancy indicator and a corresponding dormancyindicator field from the base station, and receive control informationthrough a DCI; and on the basis of the received configurationinformation, monitor the downlink control channel to perform the firstDCI field interpretation operation or the second DCI fieldinterpretation operation according to whether a condition is satisfied.

FIG. 9 is a block diagram showing a structure of a base station,according to an embodiment.

Referring to FIG. 9, the base station includes a transceiver 901, amemory 902, and a processor 903. However, the elements of the basestation may include more or fewer elements than the above elements. Inaddition, the transceiver 901, the memory 902, and the processor 903 maybe implemented into a single chip.

The transceiver 901 may transmit or receive a signal to or from aterminal. The signal may include control information and data. To thisend, the transceiver 901 may include an RF transmitter that up-convertsand amplifies a frequency of a transmitted signal and an RF receiverthat low-noise amplifies a received signal and down-converts thefrequency. In addition, the transceiver 901 may receive a signal througha wireless channel and output the signal to the processor 903, and maytransmit a signal output from the processor 903, through a wirelesschannel.

The memory 902 may store a program and data required for an operation ofthe base station. In addition, the memory 902 may store controlinformation or data included in a signal transmitted or received by thebase station. The memory 902 may be configured by a storage medium suchas a ROM, a RAM, a hard disk, a CD-ROM, a DVD, or a combination ofstorage mediums. In addition, the memory 902 may include a plurality ofmemories. The memory 902 may store a program for executing an operationfor power saving of the terminal.

The processor 903 may control a series of processes so that the basestation can operate according to embodiments described above. Theprocessor 903 may execute the program stored in the memory 902, so as tocontrol the base station to transmit, to the terminal, configurationinformation of a DCI format including a dormancy indicator and acorresponding dormancy indicator field, and transmit control informationthrough a downlink control channel; and allow the terminal to, on thebasis of the received configuration information, monitor the downlinkcontrol channel to perform the first DCI field interpretation operationor the second DCI field interpretation operation according to whether acondition is satisfied.

Methods disclosed in the claims and/or methods according to variousembodiments described in the specification of the disclosure may beimplemented by hardware, software, or a combination of hardware andsoftware.

When the methods are implemented by software, a computer-readablestorage medium for storing one or more programs (software modules) maybe provided. The one or more programs stored in the computer-readablestorage medium may be configured to be executed by one or moreprocessors within the electronic device. The at least one program mayinclude instructions that cause the electronic device to perform themethods according to various embodiments of the disclosure as defined bythe appended claims and/or disclosed herein.

The programs (software modules or software) may be stored innon-volatile memories including a RAM and a flash memory, a ROM, anelectrically erasable programmable read only memory (EEPROM), a magneticdisc storage device, a CD-ROM, DVDs, other type optical storage devices,or a magnetic cassette. Alternatively, any combination of some or all ofdifferent types of memories may form a memory in which the program isstored. Further, a plurality of such memories may be included in theelectronic device.

In addition, the programs may be stored in an attachable storage devicewhich may access the electronic device through communication networkssuch as the Internet, an intranet, a local area network (LAN), a wideLAN (WLAN), and a storage area network (SAN) or a combination thereof.Such a storage device may access the electronic device via an externalport. Further, a separate storage device on the communication networkmay access a portable electronic device.

In the above-described embodiments of the disclosure, elements may beexpressed in singular or plural forms. However, a singular form or aplural form is selected appropriately to the presented situation for theconvenience of description, and the disclosure is not limited byelements expressed in the singular form or the plural form. Therefore,either an element expressed in the plural may also include a singleelement or an element expressed in the singular may also includemultiple elements.

The embodiments of the disclosure described and shown in thespecification and the drawings have been presented to easily explain thetechnical contents of the disclosure and help understanding of thedisclosure, and are not intended to limit the scope of the disclosure.That is, it will be apparent to those skilled in the art that othermodifications and changes may be made thereto on the basis of thetechnical idea of the disclosure. Further, the above respectiveembodiments may be employed in combination, as necessary. For example,one embodiment of the disclosure may be partially combined with otherembodiments to operate a base station and a terminal. In addition, themethods proposed in the disclosure may be partially combined to operatea base station and a terminal. Further, the embodiments of thedisclosure may be applied to other communication systems, and othervariants based on the technical ideas described herein. For example,embodiments of the disclosure may be applied to LTE systems, 5G or NRsystems.

While the present disclosure has been particularly shown and describedwith reference to certain embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the disclosure as defined by the appended claims and theirequivalents.

What is claimed is:
 1. A method performed by a terminal in acommunication system, the method comprising: receiving, from a basestation, first information for a dormant bandwidth part (BWP)configuration for a secondary cell, and second information for aresource allocation type; receiving, from the base station, downlinkcontrol information (DCI) format 1_1; and identifying the DCI format 1_1as a secondary cell dormancy indication without a scheduling, in casethat a cyclic redundancy check (CRC) of the DCI format 1_1 is scrambledby a cell radio network temporary identifier (C-RNTI) or a modulationand coding scheme (MCS)-C-RNTI, and all bits of a frequency domainresource assignment field are a specific value, wherein a physicaldownlink control channel (PDCCH) on a BWP of the secondary cell is notmonitored, in case that the BWP of the secondary cell is the dormantBWP, wherein all bits of the frequency domain resource assignment fieldin the DCI format 1_1 for the secondary cell dormancy indication areequal to 0, in case that the resource allocation type is configured astype 0 based on the second information, wherein all bits of thefrequency domain resource assignment field in the DCI format 1_1 for thesecondary cell dormancy indication are equal to 1, in case that theresource allocation type is configured as type 1 based on the secondinformation, and wherein all bits of the frequency domain resourceassignment field in the DCI format 1_1 for the secondary cell dormancyindication are equal to 0 or 1, in case that the resource allocationtype is configured as a dynamic switch based on the second information.2. The method of claim 1, wherein information fields in the DCI format1_1 are used as the secondary cell dormancy indication, the informationfields comprising a modulation and coding scheme (MCS), a new dataindicator (NDI), a redundancy version (RV), a hybrid automatic repeatrequest (HARD) process number, an antenna port and a demodulationreference signal (DMRS) sequence initialization.
 3. The method of claim2, wherein the secondary cell dormancy indication is a bitmap definedbased on the information fields, each bit of the bitmap being associatedwith a secondary cell, wherein an active BWP is a dormant BWP for asecondary cell, in case that a bit for the secondary cell of the bitmapis 0, and wherein an active BWP is a BWP other than the dormant BWP forthe secondary cell, in case that the bit for the secondary cell of thebitmap is
 1. 4. The method of claim 1, wherein the DCI format 1_1 isidentified as the secondary cell dormancy indication without scheduling,in case that a carrier indicator field (CIF) included in the DCI areequal to
 0. 5. A terminal in a communication system, the terminalcomprising: a transceiver; and a controller configured to: receive, froma base station, first information for a dormant bandwidth part (BWP)configuration for a secondary cell, and second information for aresource allocation type; receive, from the base station, downlinkcontrol information (DCI) format 1_1; and identify the DCI format 1_1 asa secondary cell dormancy indication without a scheduling, in case thata cyclic redundancy check (CRC) of the DCI format 1_1 is scrambled by acell radio network temporary identifier (C-RNTI) or a modulation andcoding scheme (MCS)-C-RNTI, and all bits of a frequency domain resourceassignment field are a specific value, wherein a physical downlinkcontrol channel (PDCCH) on a BWP of the secondary cell is not monitored,in case that the BWP of the secondary cell is the dormant BWP, whereinall bits of the frequency domain resource assignment field in the DCIformat 1_1 for the secondary cell dormancy indication are equal to 0, incase that the resource allocation type is configured as type 0 based onthe second information, wherein all bits of the frequency domainresource assignment field in the DCI format 1_1 for the secondary celldormancy indication are equal to 1, in case that the resource allocationtype is configured as type 1 based on the second information, andwherein all bits of the frequency domain resource assignment field inthe DCI format 1_1 for the secondary cell dormancy indication are equalto 0 or 1, in case that the resource allocation type is configured as adynamic switch based on the second information.
 6. The terminal of claim5, wherein information fields in the DCI format 1_1 are used as thesecondary cell dormancy indication, the information fields comprising amodulation and coding scheme (MCS), a new data indicator (NDI), aredundancy version (RV), a hybrid automatic repeat request (HARD)process number, an antenna port and a demodulation reference signal(DMRS) sequence initialization.
 7. The terminal of claim 6, wherein thesecondary cell dormancy indication is a bitmap defined based on theinformation fields, each bit of the bitmap being associated with asecondary cell, wherein an active BWP is a dormant BWP for a secondarycell, in case that a bit for the secondary cell of the bitmap is 0, andwherein an active BWP is a BWP other than the dormant BWP for thesecondary cell, in case that the bit for the secondary cell of thebitmap is
 1. 8. The terminal of claim 5, wherein the DCI format 1_1 isidentified as the secondary cell dormancy indication without scheduling,in case that a carrier indicator field (CIF) included in the DCI areequal to
 0. 9. A method performed by a base station in a communicationsystem, the method comprising: transmitting, to a terminal, firstinformation for a dormant bandwidth part (BWP) configuration for asecondary cell, and second information for a resource allocation type;and transmitting, to the terminal, downlink control information (DCI)format 1_1; wherein the DCI format 1_1 is used as a secondary celldormancy indication without scheduling to indicate the terminal not tomonitor a physical downlink control channel (PDCCH) on a dormant BWP ofthe secondary cell, in case that a cyclic redundancy check (CRC) of theDCI format 1_1 is scrambled by a cell radio network temporary identifier(C-RNTI) or a modulation and coding scheme (MCS)-C-RNTI, and all bits ofa frequency domain resource assignment field are a specific value,wherein all bits of the frequency domain resource assignment field inthe DCI format 1_1 for the secondary cell dormancy indication are equalto 0, in case that the resource allocation type is configured as type 0based on the second information, wherein all bits of the frequencydomain resource assignment field in the DCI format 1_1 for the secondarycell dormancy indication are equal to 1, in case that the resourceallocation type is configured as type 1 based on the second information,and wherein all bits of the frequency domain resource assignment fieldin the DCI format 1_1 for the secondary cell dormancy indication areequal to 0 or 1, in case that the resource allocation type is configuredas a dynamic switch based on the second information.
 10. The method ofclaim 9, wherein information fields in the DCI format 1_1 are used asthe secondary cell dormancy indication, the information fieldscomprising a modulation and coding scheme (MCS), a new data indicator(NDI), a redundancy version (RV), a hybrid automatic repeat request(HARD) process number, an antenna port and a demodulation referencesignal (DMRS) sequence initialization.
 11. The method of claim 10,wherein the secondary cell dormancy indication is a bitmap defined basedon the information fields, each bit of the bitmap being associated witha secondary cell, wherein an active BWP is a dormant BWP for a secondarycell, in case that a bit for the secondary cell of the bitmap is 0, andwherein an active BWP is a BWP other than the dormant BWP for thesecondary cell, in case that the bit for the secondary cell of thebitmap is
 1. 12. The method of claim 9, wherein the DCI format 1_1 isidentified as the secondary cell dormancy indication without scheduling,in case that a carrier indicator field (CIF) included in the DCI areequal to
 0. 13. A base station in a communication system, the basestation comprising: a transceiver; and a controller configured to:transmit, to a terminal, first information for a dormant bandwidth part(BWP) configuration for a secondary cell, and second information for aresource allocation type; and transmit, to the terminal, downlinkcontrol information (DCI) format 1_1, wherein the DCI format 1_1 is usedas a secondary cell dormancy indication without scheduling to indicatethe terminal not to monitor a physical downlink control channel (PDCCH)on a dormant BWP of the secondary cell, in case that a cyclic redundancycheck (CRC) of the DCI format 1_1 is scrambled by a cell radio networktemporary identifier (C-RNTI) or a modulation and coding scheme(MCS)-C-RNTI, and all bits of a frequency domain resource assignmentfield are a specific value, wherein all bits of the frequency domainresource assignment field in the DCI format 1_1 for the secondary celldormancy indication are equal to 0, in case that the resource allocationtype is configured as type 0 based on the second information, whereinall bits of the frequency domain resource assignment field in the DCIformat 1_1 for the secondary cell dormancy indication are equal to 1, incase that the resource allocation type is configured as type 1 based onthe second information, and wherein all bits of the frequency domainresource assignment field in the DCI format 1_1 for the secondary celldormancy indication are equal to 0 or 1, in case that the resourceallocation type is configured as a dynamic switch based on the secondinformation.
 14. The base station of claim 13, wherein informationfields in the DCI format 1_1 are used as the secondary cell dormancyindication, the information fields comprising a modulation and codingscheme (MCS), a new data indicator (NDI), a redundancy version (RV), ahybrid automatic repeat request (HARD) process number, an antenna portand a demodulation reference signal (DMRS) sequence initialization. 15.The base station of claim 14, wherein the secondary cell dormancyindication is a bitmap defined based on the information fields, each bitof the bitmap being associated with a secondary cell, wherein an activeBWP is a dormant BWP for a secondary cell, in case that a bit for thesecondary cell of the bitmap is 0, and wherein an active BWP is a BWPother than the dormant BWP for the secondary cell, in case that the bitfor the secondary cell of the bitmap is
 1. 16. The base station of claim13, wherein the DCI format 1_1 is identified as the secondary celldormancy indication without scheduling, in case that a carrier indicatorfield (CIF) included in the DCI are equal to 0.